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Apple Watch
Apple Watch
from Wikipedia

Apple Watch
Apple Watch Series 8 in a Midnight aluminium case
DeveloperApple
ManufacturerContract manufacturers:
TypeSmartwatch
Release dateApril 24, 2015; 10 years ago (2015-04-24)
Units sold267.6 million (estimated, 2023)[3]
Operating systemwatchOS
DisplayRetina display with OLED
Connectivity
PowerBuilt-in rechargeable lithium-ion battery
Backward
compatibility
iPhone with the latest iOS
Websiteapple.com/watch

Apple Watch is a smartwatch developed and marketed by Apple. It has fitness tracking, health-oriented capabilities, and wireless telecommunication, and integrates with watchOS and other Apple products and services. The first Apple Watch was released in April 2015,[4][5] and quickly became the world's best-selling wearable device: 4.2 million were sold in the second quarter of fiscal 2015,[6] and more than 115 million people were estimated to use an Apple Watch as of December 2022.[7] Apple has introduced a new generation of the Apple Watch with improved internal components [8] – labeled by Apple as a 'Series', with certain exceptions.[a]

Each Series has been initially sold in multiple variants defined by the watch casing's material, colour, and size (except for the budget watches Series 1 and SE, available only in aluminium,[9][12] and the Ultra, available only in 49 mm titanium[11]), and beginning with Series 3, by the option in the aluminium variants for LTE cellular connectivity, which comes standard with the other materials.[13] The band included with the watch can be selected from multiple options from Apple, and watch variants in aluminium co-branded with Nike and in stainless steel co-branded with Hermès are also offered, which include exclusive bands and colours. Any user may use digital watch faces carrying those companies' branding.[13]

The Apple Watch operates in conjunction with the user's iPhone for functions such as configuring the watch and syncing data with iPhone apps, but can separately connect to a Wi-Fi network for data-reliant purposes, including communications, app use, and audio streaming.[14][15] LTE-equipped models can also perform these functions over a mobile network, and can make and receive phone calls independently when the paired iPhone is not nearby or is powered off.[b] The oldest iPhone model that is compatible with any given Apple Watch depends on the version of the operating system installed on each device.[18] As of September 2025, new Apple Watches come with watchOS 26 preinstalled and require an iPhone running iOS 26, which is compatible with the iPhone 11 or later.[19][20]

The Apple Watch is the only smartwatch fully supported for the iPhone, as Apple restricts the APIs available in other smartwatches, so other smartwatches always have less functionality.[21]

Development

[edit]

Apple design chief Jony Ive became interested in building a watch shortly after Steve Jobs's death in October 2011.[22] That December, The New York Times reported that Apple was exploring various ideas, including a "curved-glass iPod that would wrap around the wrist", which users would interact with through the Siri voice assistant, and which "could relay information back to the iPhone".[23] In February 2013, the NYT and The Wall Street Journal again confirmed that Apple was working on a smartwatch with a curved display,[24] and Bloomberg News said the team had grown to about 100 designers.[25]

In March 2013, Apple hired ex-Adobe chief technology officer Kevin Lynch, reporting to Bob Mansfield,[26] to lead the watch project, which would become the company's first major new product without input from late co-founder Steve Jobs.[22] Apple started the project without specific use cases in mind, not knowing what problems the watch would solve, but felt that "technology was going to move onto the body", according to Alan Dye, who was in charge of its user interface. According to Kevin Lynch, the team felt people spent too much time on their phone, nagged by notifications, and a watch would provide "that level of engagement [...] in a way that's a little more human, a little more at the moment when you're with somebody".[22]

In July 2013, Financial Times reported that Apple had begun hiring more employees to work on the smartwatch, and that it was targeting a retail release in late 2014.[27]

The software evolved more quickly than the hardware. To test it, the team created a prototype, an iPhone strapped to the wrist with Velcro, which showed the Apple watch software in its true size and an onscreen watch crown for input. The crown was later turned into a physical dongle plugged into the headphone jack. Early on, the user interface and bundled apps were inspired by the iPhone, but they were too complex and underwent three rounds of redesign to avoid awkwardly long interactions that would annoy users. The team worked on notification vibrations and sounds for more than a year, attempting to make them reflect the nature of different notifications. They also added a way to show a contextual menu by pressing the display more deeply, called Force Touch. In contrast with Apple's usually narrow design options, the team thought a watch would need to appeal to users' diverse tastes in fashion, so they opted to give a choice of bands, models (like the gold-plated Apple Watch Edition), and watch faces.[22]

Unveiling and release

[edit]

In April 2014, Apple CEO Tim Cook told The Wall Street Journal that the company was planning to launch new products that year, but revealed no specifics.[28]

In June 2014, Reuters reported that production of a smartwatch product was expected to begin in July for an October release.[29]

During a September 2014 press event where the iPhone 6 was also presented, the new watch product was introduced by Tim Cook's "one more thing" section. After a video focusing on the design process, Cook reappeared on stage wearing an Apple Watch.[30]

In comparison to other Apple products and competing smartwatches, marketing of the Apple Watch promoted the device as a fashion accessory.[31] Apple later focused on its health and fitness-oriented features, in an effort to compete with dedicated activity trackers. The watchOS 3 added fitness tracking for wheelchair users, social sharing in the Activity app, and a Breathe app to facilitate mindfulness.[32]

The device was not branded as "iWatch", which would have put it in line with its product lines such as iPod, iPhone, and iPad. In the United States, the "iWatch" trademark is owned by OMG Electronics – who was crowdfunding a device under the same name; it is owned in the European Union by Irish firm Probendi.[33] In July 2015, Probendi sued Apple Inc. for trademark infringement, arguing that through keyword advertising on the Google search engine, it caused advertising for the Apple Watch to appear on search results pages when users searched for the trademarked term "iWatch".[34]

Release

[edit]

Pre-orders for the Apple Watch began on April 10, 2015, with the official release on April 24.[35] Initially, it was not available at the Apple Store; customers could make appointments for demonstrations and fitting, but the device was not in-stock for walk-in purchases and had to be reserved and ordered online. CNET felt that this distribution model was designed to prevent Apple Store locations from having long lineups due to the high demand.[36][37] The first ever retail store to display the Apple Watch to the public was Colette in Paris.[38] Later on, selected models were available in limited quantities at luxury boutiques and authorized resellers.[39]

On June 4, 2015, Apple announced that it planned to stock Apple Watch models at its retail locations.[37]

On August 24, 2015, Best Buy announced that it would begin stocking Apple Watch at its retail stores by the end of September.[40] Both T-Mobile US and Sprint also announced plans to offer Apple Watch through their retail stores.[41]

In September 2015, Apple launched a new subset of Apple Watch, with a stainless steel body and leather band, in collaboration with Hermès.[42] The following year, Apple launched another subset of Apple Watches in collaboration with Nike dubbed "Apple Watch Nike+". Both subsets featured cosmetic customization, but otherwise functioned like standard Apple Watches.[43]

Apple Watch went on sale in India in November 2015.[44] The device also launched in Chile, the Philippines, Indonesia, and South Africa.[45]

Hardware

[edit]

Design and materials

[edit]
Series 4 (40 mm, aluminum, Space Gray color)

Each series of Apple Watch is offered in multiple variants, distinguished by the casing's material, color, and size,[46] with special bands and digital watch faces available for certain variants co-branded with Nike and Hermès, which are also sometimes accompanied by other unique extras, like stainless steel charging pucks, premium packaging, and exclusive color basic bands.[47]

Originally at launch, the Apple Watch was marketed as one of three "collections", designating the case material. In order of increasing cost, the collections were:[citation needed]

  • Apple Watch Sport (aluminium case)
  • Apple Watch (stainless-steel case)
  • Apple Watch Edition (originally released as an 18kt gold casing with newer materials in later models)

Starting with Series 1/Series 2, Apple dropped the "Sport" moniker from the branding (apart from the sport bands), and the Apple Watch was available with either an aluminum (lowest cost) or stainless steel case. "Apple Watch Edition" branding still exists, but now refers to watch casings made from ceramic or titanium.[48]

Apple did not explicitly market the first-generation Apple Watch as being waterproof, stating that it can withstand splashes of water (such as rain and hand washing), but does not recommend submersion (IPX7). Apple introduced a higher level of water resistance with the release of the Apple Watch Series 2, and the device was explicitly advertised as being suitable for swimming and surfing.[49] The Series 7 also includes an IP6X certification for dust resistance.[50][51]

Size

[edit]

Since the introduction of the Apple Watch, it has been available in two sizes (Apple Watch Ultra being the exception), primarily affecting screen resolution and area. The smaller size at launch was 38 mm (1.5 in), referring to the approximate height of the watch case; the larger size was 42 mm (1.7 in). Starting with Series 4, the two nominal sizes changed to 40 and 44 mm (1.6 and 1.7 in).[52][53] The nominal sizes changed again with the introduction of Series 7: 41 and 45 mm (1.6 and 1.8 in);[54] and yet again in 2024 with the launch of the Series 10 at 42 and 46 mm (1.7 and 1.8 in).[55]

The overall shape and width of the watch have not changed significantly since its release, so customizable bands and accessories are typically compatible with any Apple Watch of the same size class. Bands that fit the smaller size class (38, 40, 41 and 42 mm (1.5, 1.6, 1.6 and 1.7 in) watches) and larger size class (42, 44, 45 and 46 mm (1.7, 1.7, 1.8 and 1.8 in) watches) are generally interchangeable within the class.[56] The casing of the watch includes a mechanism to allow the user to change the straps without special tools.[citation needed]

Input and sensors

[edit]
Underside of three Apple Watches, showing the digital crown and updates to the back sensors; L–R: Series 3, 5, and 6

For input, the Watch features a "digital crown" on one side, which can be turned to scroll or zoom content on screen, and pressed to return to the home screen or display recently used apps. Next to the crown (on the same side of the watch) is the Side Button, which can be used to access Control Center and the contactless payment service Apple Pay.[57] The Watch also prominently features a touchscreen; before Series 6/SE, the screen included Force Touch technology, which enabled the display to become pressure-sensitive and therefore capable of distinguishing between a tap and a press for displaying contextual menus.[58] Force Touch has since been physically removed in Watch Series 6 and Watch SE,[59] and has been disabled via software on Watch Series 5 and earlier on models supporting watchOS 7.[60]

Additional sensors integrated into the Watch include an accelerometer, gyroscope, and barometer, which are used to determine device orientation, user movement, and altitude.[61] The back of all Apple Watches are equipped with a Heart Rate Monitor, which projects infrared and green light from light-emitting diodes (LEDs) onto the user's skin and photodiodes measure the varying amount of light reflected. Because blood absorbs green light and reflects red light, the amounts of each type of reflected light are compared to determine heart rate. The Watch adjusts the sampling rate and LED brightness as needed.[61] Starting with the Series 4, Apple added electrical sensors to the Digital Crown and back, allowing the Watch to take electrocardiogram (ECG) readings;[62] the device won FDA clearance in October 2018, becoming the first consumer device capable of taking an ECG.[63] A blood oxygen monitor was added with the Series 6 in 2020, albeit as a "wellness" device not capable of diagnosing a medical condition.[64] The blood oxygen monitor added red LEDs to the back, allowing the watch to determine oxygen levels by measuring blood color.[65] The Watch SE reverted to the capabilities of the Series 3, dropping the electrical sensors and blood oxygen monitor.[66]

Battery

[edit]

Apple rates the device's battery for 18 hours of mixed usage.[58][67] Apple Watch is charged by means of inductive charging.[4] If the watch's battery depletes to less than 10 percent, the user is alerted and offered to enable Low Power Mode, which allows the user to continue to use the watch while some features are disabled. The watch then reverts to its original mode when the battery is sufficiently charged.[68]

Bands

[edit]

Apple Watch comes with an included band (strap) to attach it to the user's wrist. The proprietary band attachment mechanism allows swapping models by holding down the connectors on the bottom of the watch and sliding the band pieces out.[69] Apple produces bands in a variety of materials and colors; however, third-party bands are still compatible when using Apple's design guidelines.[70] Bands designed for the original Series 1–3 38 mm and 42 mm case sizes are compatible with the Series 4–6 40 mm and 44 mm cases, as well as the Series 7 41 mm and 45 mm cases, respectively.[71]

Starting with Apple Watch Series 5, Apple introduced the online Apple Watch Studio, which allows customers to mix and match bands on purchase, eliminating the need to purchase a specific combination of case and band design, and allowing for a simplification of packaging (since Apple Watch Series 4 in 2018).[72]

Models

[edit]
An Apple Watch "Discovery" table at an Apple Store

Apple Watch models have been divided into five "collections": Apple Watch (1st generation-present), Apple Watch Sport (1st generation), Apple Watch Nike+ (Series 2-Series 7, combined into Apple Watch since Series 8), Apple Watch Hermès (1st generation-present, including Apple Watch Ultra 2, excluding Apple Watch SE and Apple Watch Ultra), and Apple Watch Edition (1st generation-Series 7, excluding Apple Watch SE).[citation needed] They are differentiated by combinations of cases, bands, and exclusive watch faces; Apple Watch comes with either aluminum or stainless steel cases, and various watch bands (only stainless steel was offered for Apple Watch 1st generation); Apple Watch Sport came with aluminum cases and sport bands or woven nylon bands; Apple Watch Nike+ comes with aluminum cases and Nike sport bands or sport loops; Apple Watch Hermès uses stainless steel cases and Hermès leather watch bands (also included is an exclusive Hermès orange sport band); and Apple Watch Edition came with ceramic cases and various bands (the Apple Watch Edition used 18 karat yellow or rose gold).[73] With the Series 5, the Edition tier was expanded with a new titanium case.[citation needed]

Apple Watch Series 1 models were previously only available with aluminum cases and sport bands.[74]

As of Series 3, each Apple Watch model in aluminum, the least expensive casing, is available either with or without LTE cellular connectivity, while the models with the other casing materials available (stainless steel and sometimes ceramic and titanium) always include it.[16][75]

Each model through Series 3 comes in a 38mm or 42mm size option, with the larger size having a slightly larger screen and battery.[58] The Series 4 was updated to 40mm and 44mm models, respectively. The Series 7 has been updated to 41mm and 45mm models. The Series 10 has been updated to 42mm and 46mm models.[76] Each model has various color and band options. Featured Apple-made bands include colored sport bands, sport loop, woven nylon band, classic buckle, modern buckle, leather loop, Milanese loop, and a link bracelet.[58]

First generation

[edit]
Apple S1

The 1st generation Apple Watch (colloquially referred to as Series 0) uses the single-core S1 system-on-chip. It does not have a built-in GPS chip, instead relying on a paired iPhone for location services. It features a new linear actuator hardware from Apple called the "Taptic Engine", providing realistic haptic feedback when an alert or a notification is received, and is used for other purposes by certain apps.[58] The watch is equipped with a built-in heart rate sensor, which uses both infrared and visible-light LEDs and photodiodes.[77]

All versions of the first-generation Apple Watch have 8 GB of storage; the operating system allows the user to store up to 2 GB of music and 75 MB of photos. When the Apple Watch is paired with an iPhone, all music on that iPhone is also available to be controlled and accessed from the Apple Watch.[78] Software support for the first Apple Watch ended with watchOS 4.3.2.[79]

Second generation (Series 1 and 2)

[edit]
Apple S2

The second-generation Apple Watch has two models: the Apple Watch Series 1 and Apple Watch Series 2.

The Series 1 has a variant of the dual-core Apple S2 processor with GPS removed, known as the Apple S1P. It has a lower starting price than first generation.[80] The Series 1 was sold only in Aluminium casings.[citation needed]

The Series 2 has the dual-core Apple S2 processor, water resistance to 50 meters, a display twice as bright, at 1,000 nits, and a GPS receiver.[80][49] The Series 2 was sold in casings of anodized aluminum, stainless steel and ceramic.[citation needed]

The Apple Watch Edition Series 2 is the first Apple Watch model to add the new White ceramic case color option. Both Yellow Gold and Rose Gold 18K gold case color options have been removed.[citation needed]

The Apple Watch Nike+ Series 2 is the first Apple Watch model available as the Nike, Inc. collaborate special option.[citation needed]

The Apple Watch Series 1 and Apple Watch Series 2 are the final Apple Watch models available with Yellow Gold and Rose Gold aluminum case color options. They have an advertised 18 hours of battery life.[citation needed]

The software support for both Apple Watch Series 1 and Apple Watch Series 2 ended with watchOS 6.3.[citation needed]

Third generation (Series 3)

[edit]
Apple S3

The Apple Watch Series 3 features a faster processor, the dual-core S3, Bluetooth 4.2 (compared to 4.0 on older models), a built-in altimeter for measuring flights of stairs climbed, increased RAM size, and is available in a variant with LTE cellular connectivity. Siri can speak through the onboard speaker on Apple Watch Series 3 due to the increased processing speed of the Watch.[81]

Series 3 features LTE cellular connectivity for the first time in an Apple Watch, enabling users to make phone calls, iMessage, and stream Apple Music and Podcasts directly on the watch, independent of an iPhone. The LTE model contains an eSIM[82] and shares the same mobile number as the user's iPhone.[83]

The Apple Watch Series 3 is the first Apple Watch model to add the new Gold aluminum case color option to match the color introduced with the iPhone 8 in 2017. Both Yellow Gold and Rose Gold aluminum case color options have been removed. It is now available in Space Gray, Silver, and Gold aluminum case color options, available in Space Black and Silver stainless steel case color options.[citation needed]

The Apple Watch Edition Series 3 is the first and only Apple Watch model to add the new Gray ceramic case color option. It is available in White and Gray ceramic case color.[citation needed]

The software support for the Apple Watch Series 3 ended with watchOS 8.8.1.[84]

Fourth generation (Series 4)

[edit]
Apple Watch Series 4 with California dial[85]

The Apple Watch Series 4[86] is the first prominent redesign of the Apple Watch, featuring larger displays with thinner bezels and rounded corners, and a slightly rounder, thinner chassis with a redesigned ceramic back. Internally, there is a new S4 64-bit dual-core processor, capable of up to double the S3's performance, upgraded 16 GB storage, and a new electrical heart sensor. The microphone was moved to the opposite side between the side button and the digital crown to improve call quality. Other changes include the digital crown incorporating haptic feedback with the Apple Haptic Engine, and include the new Apple-designed W3 wireless chip.[citation needed]

The ECG system has received clearance from the United States Food and Drug Administration, a first ever for a consumer device,[87] and is supported by the American Heart Association.[88] The Series 4 can also detect falls, and can automatically contact emergency services unless the user cancels the outgoing call.[citation needed]

The watch received mostly positive reviews from critics. TechRadar gave it a score of 4.5/5, calling it one of the top smartwatches, while criticizing the short battery life.[89] Digital Trends gave it a score of 5/5, calling it Apple's best product and praising the design, build quality, and software, among others, while criticizing the battery life.[90] CNET gave it a score of 8.2/10, calling it the "best overall smartwatch around", while criticizing the battery life and lack of watch face options.[91] T3 gave it a score of 5/5, calling it a "truly next-gen smartwatch" due to its thinner body and bigger screen compared to the Series 3, and health features.[92]

The Apple Series 4 is the first Apple Watch model to add the new Gold stainless steel color option to match the color introduced with the iPhone XS in 2018. It is now available in Space Gray, Silver, and Gold aluminum case color options, available in Space Black, Silver, and Gold stainless steel case color options. All the ceramic case color options have been removed until the launch of the Apple Watch Edition Series 5 in 2019.[citation needed]

Software support for the Apple Watch Series 4, Series 5, and the first-generation Apple Watch SE ended with watchOS 10.6.1.[93]

Fifth generation (Series 5 and first-generation SE)

[edit]
Apple S5

The Apple Watch Series 5 was announced on September 10, 2019.[94] Its principal improvements over its predecessor were the addition of a compass and an always-on display with a low-power display driver capable of refresh rates as low as once per second. Additional new features include International Emergency Calling, enabling emergency calls in over 150 countries, a more energy-efficient S5 processor,[95] improved ambient light sensor, and storage doubled to 32 GB. The release of the Series 5 also brought back the "Edition" model, with a ceramic model absent from the previous generation. A new titanium model was also included in two colors: natural and Space Black.[96]

At its September 2020 product introduction event, Apple also announced the Apple Watch SE, a lower-cost model, similar to the iPhone SE.[97] The SE incorporates the same always-on altimeter as the Series 6,[98] but uses the previous-generation S5 processor and previous- (i.e. second) generation optical heart rate sensor; does not include ECG and blood oximeter sensors or an always-on display; and does not include ultra-wideband (UWB) or 5 GHz Wi-Fi communication capabilities.[citation needed]

The Series 5 and above (including the SE model introduced in 2020) also incorporate enhanced hardware- and software-based battery and performance management functionality.[99]

Critics generally gave it a positive review. CNET gave it a score of 4/5, concluding, "The Apple Watch continues to be one of the best smartwatches, but it remains limited by being an iPhone accessory for now."[100] Digital Trends gave it a score of 4.5/5.[101] The Verge gave it a score of 9/10.[102]

The Apple Watch Series 5 was available in Space Gray, Silver, and Gold aluminum case color options, as well as Space Black, Silver, and Gold stainless steel case color options.[citation needed]

The Apple Watch Edition Series 5 was the final Apple Watch model available with a White ceramic case color option. It was the first Apple Watch model to add the new Natural and Space Black titanium case color options.[citation needed]

The first-generation Apple Watch SE was discontinued following the release of the second-generation Apple Watch SE in 2022.[citation needed]

Software support for the Apple Watch Series 4, Series 5, and the first-generation Apple Watch SE ended with watchOS 10.6.1.[93]

Sixth generation (Series 6)

[edit]
Apple S6
The inside of an Apple Watch 6

The Apple Watch Series 6 was announced on September 15, 2020, during an Apple Special Event and began shipping on September 18. Its principal improvement over its predecessor is the inclusion of a sensor to monitor blood oxygen saturation.[103]

Additional features include a new Apple S6 utilizing the energy-efficient Thunder cores from the A13 Bionic that is up to 20% faster than the Apple S4 and Apple S5,[97] a 2.5× brighter always-on display, and an always-on altimeter.[104] The S6 incorporates an updated, third generation optical heart rate sensor and also enhanced telecommunication technology, including support for ultra-wideband (UWB) via Apple's U1 chip (which is used to locate and communicate with other devices),[105] and the ability to connect to 5 GHz Wi-Fi networks. The Series 6 watch was updated with faster charging hardware, such that it completes charging in ~1.5 hours.[106] Force Touch hardware was removed, consistent with the removal of all Force Touch functionality from watchOS 7.

The Apple Watch Series 6 is the final Apple Watch model available with Space Gray and Gold (introduced with the iPhone 8 in 2017) aluminum case color options. It is the first time adding the Product Red and Blue aluminum case color options. It is available in Space Gray, Silver, Gold, Blue, and Product Red aluminum case color options, available in Graphite, Silver, and Gold stainless steel case color options. The Gold stainless steel case color option is now in classic yellow gold, and the Graphite stainless steel case color option is the new color, replacing the Space Black color before the introduction of the iPhone 12 Pro in 2020.[citation needed]

The Apple Watch Edition Series 6 is now available in Natural and Space Black titanium case color options. The ceramic case option was removed.[citation needed]

Seventh generation (Series 7)

[edit]
Apple S7

The Apple Watch Series 7 was announced on September 14, 2021, during an Apple Special Event.[107] Pre-orders opened on October 8, with earliest shipping dates starting on October 15.[citation needed]

Succeeding from the Apple S6, the Apple S7 is the second time utilizing the energy-efficient Thunder cores from the A13 Bionic.[citation needed]

Enhancements relative to the prior-generation Series 6 watch include a more rounded design with a case 1 mm larger than the Series 6; a display that is 70% brighter indoors and approximately 20% larger; improved durability via a crack-resistant front crystal;[108] IP6X certification for resistance to dust; 33% faster charging via improved internal electronics and an enhanced, USB-C based fast-charging cable; support for BeiDou (China's satellite navigation system); and the availability of an on-screen keyboard that can be tapped or swiped.[109] The Series 7 is also equipped with new hardware that enables ultra-rapid, short-range wireless data transfer at 60.5 GHz, though Apple has not fully explained this new functionality.[110]

The Apple Watch Edition Series 7 is the final Apple Watch model to be available in Natural and Space Black titanium case color options.[citation needed]

The Apple Watch Series 7 is now available in Midnight, Starlight, Blue, Green, and Product Red aluminum case color options, available in Graphite, Silver, and Gold (introduced with the Apple Watch Series 6 and the iPhone 12 Pro in 2020) stainless steel case color options. Both Space Gray and Gold (introduced with iPhone 8 in 2017) aluminum case color options have been removed. The Silver aluminum case color option was unavailable until the launch of the Apple Watch Series 8 in 2022.[citation needed]

Eighth generation (Series 8, SE (2nd generation) and Ultra)

[edit]
Apple S8

The Apple Watch Series 8, the Apple Watch SE 2 (formerly the Apple Watch SE (2nd generation)), and the Apple Watch Ultra were announced during Apple's "Far out" event on September 7, 2022. Pre-orders opened on the same day, with the Series 8 and 2nd gen SE shipping on September 16, while the Ultra shipped on September 23.[111]

Succeeding from the Apple S7, the Apple S8 is the final processor of the Apple Watch to utilize the energy-efficient Thunder cores from the A13 Bionic.[citation needed]

Enhancements in the Series 8, relative to the prior-generation Series 7 watch, include a new temperature sensor and more precise accelerometers, and Crash Detection. Aluminum case models are available in Midnight, Silver, Starlight, and Product Red, and the stainless steel models are available in gold, silver, and graphite finishes. The Blue and Green case colors are discontinued, and the Series 8 is not available with a titanium case.[112]

The Apple Watch Ultra is a new high-end model which Apple positioned towards endurance athletes and outdoor recreation (competing with offerings from companies such as Garmin and Polar); it shares most of its hardware with the Series 8, but it has a larger display and 49 mm band, a rugged titanium casing, a brighter display with a flat front crystal, an additional "Action" button that can be mapped to different apps and functions, integrated multi-band GPS, a water temperature sensor, and a larger battery which Apple rated at 36 hours of usage without using power saving modes.[113]

The second-generation Apple Watch SE is available in Midnight, Silver, and Starlight case color options. The Space Gray and Gold case color options have been discontinued. It retains the form factor of the previous SE, which was itself very similar to the Series 4, 5, and 6.[114]

Ninth generation (Series 9 and Ultra 2)

[edit]

The Apple Watch Series 9 and Ultra 2 were announced during Apple's "Wonderlust" event on September 12, 2023.[107] Both of these Apple Watch models have the new Apple S9 system-in-package utilizing the energy-efficient Sawtooth cores from the A16 Bionic with a faster GPU and a four-core Neural Engine, improved power efficiency, and a second-generation Ultrawide Band chip (shared with iPhone 15) with improved precision and a farther range. Their displays have a higher maximum brightness than their predecessors. Both Apple Watch Series 9 and Apple Watch Ultra 2 ship with watchOS 10; they support on-device Siri and a new "double tap" gesture using the index finger and thumb.[107][115]

Before the announcement of watchOS 26 at Apple's WWDC 2025, a new feature, "wrist flick" gesture (using the wrist to quickly turn over and back to dismiss the incoming notification) will be available on the Apple Watch Series 9 and Apple Watch Ultra 2 alongside the Apple Watch Series 10.[5]

Aluminum case models are available in Midnight, Pink, Starlight, Silver, and Product Red color options, while the stainless steel models are available in gold, silver, and graphite finishes.[citation needed]

For legal reasons, blood oxygen monitoring was not available on Apple Watch Series 9 and Ultra 2 models sold in the United States after January 18, 2024.[116]

Following a ruling by the International Trade Commission on a lawsuit regarding the blood oxygen monitoring feature, Apple temporarily stopped selling Apple Watch Series 9 and Ultra 2 on December 21, 2023, ahead of an import ban going into effect on December 26, 2023. At the time, 9to5Mac reported, "Apple says that the ITC’s ban only impacts sales of the Apple Watch Series 9 and Apple Watch Ultra 2 because those devices offer blood oxygen monitoring capabilities." A US Federal Appeals Court paused the import ban pending a US Customs and Border Protection ruling on whether Apple's changes would be enough to avoid the patent dispute, and Apple resumed sales on December 27, 2023.[citation needed]

On August 14, 2025, Apple reintroduced blood oxygen monitoring for affected Series 9, Series 10, and Ultra 2 Apple Watches with the iOS 18.6.1 and watchOS 11.6.1 software updates. To circumvent patent disputes, the redesigned app no longer analyzes blood oxygen data through the on-device app. Raw data is collected by the Apple Watch, then "measured and calculated on the paired iPhone."[117]

Carbon neutrality claims

[edit]

Apple markets the Series 9 and Ultra 2 as its first-ever carbon-neutral products (depending on the selected case material and band) due to a combination of cutting the carbon dioxide emissions per watch manufactured and sold (Apple claims a reduction of 78% for the Series 9 and 81% for the Ultra 2[121]) and the company's purchases of forestry and nature-based carbon offsets and credits—which some criticized for being misleading due to reliability issues in carbon accounting for forestry carbon offsets.[119]

Most of Apple's claimed emissions reductions were driven by renewable energy requirements imposed on suppliers;[118][120] other factors include increased use of recycled materials, and a lower reliance on shipping products by plane, which is highly carbon-intensive.[119] Apple says the watches' manufacturing relies on "100% clean electricity", though this partly relies on Apple investing in clean-energy projects to offset suppliers' use of electricity produced from fossil fuels. NewClimate Institute, a non-profit, said Apple's "100 per cent clean energy" claim was "highly contentious, since Apple’s major suppliers continue to have very low renewable electricity shares".[122]

The carbon offsets used by Apple follow standards set by Verra,[123] the Climate, Community & Biodiversity Alliance, and the Forest Stewardship Council.[118] However, some investigative reporting has indicated that 94% of Verra's rainforest carbon offsets were allegedly "worthless" and that the standard may worsen global warming.[124][123] Niklas Kaskeala, chair of the non-profit Compensate Foundation, said Apple's tree-planting offsets had "systemic flaws"; the Financial Times found that in one Apple conservation scheme, newly planted trees were chopped down within a decade, releasing absorbed carbon back into the atmosphere, that most of the planted trees were eucalyptus, posing monoculture concerns, and that only 1% of the land was dedicated to regrowing native tree species.[122]

On September 20, 2023, the European Union announced that it would ban most uses of the term "carbon neutral" in advertising by 2026, including claims that are based on carbon offsets, to address greenwashing and misleading advertising. This decision was praised by Monique Goyens, director-general of EU consumer group BEUC, who also called Apple's claims "bogus" and scientifically inaccurate. Gilles Dufrasne, policy officer at non-profit Carbon Market Watch, said it was "misleading to consumers" for Apple to give "the impression that buying the Watch has no impact on the climate at all", based on what he described as "accounting tricks". Other environmental groups criticized Apple's emphasis on carbon emissions without accounting for e-waste, due to the difficulty of repairing these products.[122][125][126] Berkeley Carbon Trading Project director Barbara Haya praised the products' ~80% emissions reduction, but also criticized Apple's use of the term "carbon neutral" in advertising.[119]

Tenth generation (Series 10)

[edit]
Apple Watch Series 10 (front view)
Apple Watch Series 10 (back view)

The Apple Watch Series 10 was announced at an Apple's "It's Glowtime" event on September 9, 2024. The device features a thinner design than previous models, measuring 10% thinner than the Series 9. It has the largest display Apple has built for a wearable device, including the Apple Watch Ultra, with up to 30% more screen area. The display allows for an additional line of text, enhancing the visibility of messages, mail, and news.[citation needed]

Succeeding from the Apple S9, the Apple S10 is the second time utilizing the energy-efficient Sawtooth cores from the A16 Bionic.[citation needed]

The Series 10 introduces a wider aspect ratio with rounded corners for both the display and case. The display is also 40% brighter when viewed at an angle, improving visibility, and updates once per second in Always On mode, compared to the previous rate of once per minute.[127]

Apple also introduced a new glossy aluminum finish in jet black, polished using silicon nanoparticles for a specialized surface shine. Other finish options include rose gold and silver aluminum, which are up to 10% lighter than previous models. Additionally, a new titanium finish, which is 20% lighter and carbon-neutral, replaces the stainless steel option from earlier generations.[citation needed]

The Apple Watch Series 10 retains 50 meters of water resistance and is the fastest-charging Apple Watch to date, reaching 80% battery in 30 minutes. The device features an 18-hour battery life.[citation needed]

The Apple Watch Series 10 also includes a sleep apnea detector, pending FDA approval, which is also planned to be supported by the Apple Watch Series 9 and the Apple Watch Ultra 2.[citation needed]

To enhance phone call quality, the Series 10 incorporates a neural network that suppresses background noise for clearer conversations. The fitness features have been expanded to include tracking for kayakers, canoers, and rowers, along with a Tides app and new depth and water temperature sensors.[citation needed]

Before the announcement of the watchOS 26 at Apple's WWDC 2025, a new feature "wrist flick" gesture (using the wrist to quickly turn over and back to dismiss the incoming notification) will be available on the Apple Watch Series 10 alongside the Apple Watch Series 9 and Apple Watch Ultra 2.[128]

Prices for the Apple Watch Series 10 start at $399, with preorders available immediately. The device was released on September 20, 2024.[129]

The Apple Watch Series 10 has been subject to a sales ban in Indonesia since October 2024.[130]

Eleventh generation (Series 11, SE 3, and Ultra 3)

[edit]

The eleventh-generation Apple Watch was introduced on September 9, 2025, alongside the third-generation Apple Watch Ultra and SE, and was released on September 19, 2025.[131]

The Apple Watch Series 11 additionally added the Space Gray color option, in addition to the existing Jet Black, Rose Gold, and Silver color options that were introduced with the Apple Watch Series 10.

The third-generation Apple Watch SE is the first Apple Watch model since the Apple Watch Series 7 to not come in the silver color option. It is the first Apple Watch SE model to feature the Always-On display technology.

The Apple Watch Ultra 3 has the same enclosure design as its predecessors.

Succeeding from the Apple Watch Series 10, among the Apple Watch Series 11, Apple Watch SE (third-generation), and Apple Watch Ultra 3, use the Apple S10 chip for the second time. They are the first time using the 5G connectivity.

Software

[edit]

watchOS is a distinct operating system designed specifically for Apple Watch. While based on iOS, which is used in iPhones, it offers a tailored experience for the smaller screen and wrist-worn form factor. Telling time is a core function with various watch faces to choose from. and it can view and respond to notifications from an iPhone directly on a watch. watchOS has many extensive health and fitness tracking features like heart rate monitoring, workout programs, and activity rings to stay motivated. The App Store lets you download and use various apps specifically designed for Apple Watch, covering fitness, communication, news, and more. watchOS works seamlessly with an iPhone for functions like making calls, sending texts, unlocking an iPhone, and using Apple Pay. Apple frequently releases updates to watchOS, bringing new features, bug fixes, and security improvements. One can update a watch through the Watch app on an iPhone or directly on the Apple Watch itself (if it has watchOS 6 or later).[132]

Apple Watch runs watchOS, whose interface is around a home screen with circular app icons, which can be changed to a list view in the device's settings. The OS can be navigated using the touchscreen or the crown on the side of the watch.[58] During its debut, the first generation Apple Watch needed to be paired with an iPhone 5 or later running iOS 8.2 or later; this version of iOS introduced the Apple Watch app, which is used to pair the watch with an iPhone, customize settings and loaded apps, and highlight compatible apps from the App Store.[58]

The Apple Watch is capable of receiving notifications, messages, and phone calls via a paired iPhone.[58] "Glances" allowed users to swipe between pages containing widget-like displays of information; however, this feature was replaced by a new Control Center. watchOS also supports Handoff to send content from Apple Watch to an iOS or macOS device,[58] and act as a viewfinder for an iPhone camera,[133] Siri is also available for voice commands, and is capable of responding with voice prompts on the Series 3 watches.[58] Apple Watch also supports Apple Pay, and enables its use with older iPhone models that do not contain near-field communication (NFC) support.[58]

Apple Watch's default apps are designed to interact with their iOS counterparts, such as Mail, Phone, Calendar, Messages, Maps, Music, Photos, Reminders, Remote (which can control iTunes and Apple TV), Stocks, and Wallet.[58] Using the Activity and Workout apps, a user can track their physical activity and send data back to the iPhone for use in its Health app and other HealthKit-enabled software.[58] With watchOS 3, Reminders, Home, Find My Friends, Heart Rate, and Breathe were added to the stock apps.[citation needed]

Version history

[edit]

At WWDC 2015, Tim Cook announced watchOS 2; described by CNET as a "significant revamp", it included a new software development kit that allows more direct access to the device's hardware, new watch faces, the ability to reply to an e-mail, and other features.[134] watchOS 2 was released in September 2015.[135] Following the software update, some users experienced issues with lag.[136]

watchOS 3 was announced at WWDC 2016, with a priority on performance. Users can keep apps running in memory as well as receive background updates and refreshed information. Other updates include a new Dock invoked with the side button to replace the performance-laden Glances, an updated Control Center, and new reply options on Messages. Several new watch faces have also been added, including Minnie Mouse, along with the ability to switch watch faces from the lock screen simply by swiping. A new feature called SOS allows users to hold the dock button to make a call to the local emergency line and pull up the user's Medical ID. Another feature is Activity Sharing, which allows sharing of workouts with friends and even sending their heartbeats to one another. A new app called Breathe guides users through breathing exercises throughout the day, with visuals and haptic feedback. It was made available to the public in September 2016.[citation needed]

watchOS 3.1 was released to the public in October 2016, and watchOS 3.2 was released in March 2017.[137] Both updates added minor improvements and bug fixes.

watchOS 4 was announced at WWDC 2017 and released to the public in September 2017. watchOS 4 features a proactive Siri watch face, personalized activity coaching, and an entirely redesigned music app. It also introduces Apple GymKit, a technology platform to connect workouts with cardio equipment.[citation needed]

watchOS 4.3 was released in March 2018. It introduced support for Nightstand mode in portrait orientation. It brought back the ability for music playing on the iPhone to be controlled using the Music app on the Apple Watch and also enabled control of playback and volume on Apple's HomePod. Other new features included a new charging animation and a new app loading animation. Activity data was added to the Siri watch face, and the battery complication more accurately reports battery life.[citation needed]

watchOS 5 was first shown to the public at the San Jose WWDC developer conference held by Apple. It introduced an instant watch-to-watch walkie-talkie mode, an all-new Podcasts app, raise-wrist-to-speak Siri, a customizable Control Center, and the ability to access the notification center and control center from apps. Other features included support for WebKit to view web pages, six new watch faces, and new workout running features.[138] It was released to the public in September 2018.[139] On the newest release of watchOS beta, the sleep feature was shown on screen, which would eliminate the need to use third-party apps.

watchOS 6 was released to the public in September 2019. It introduced more native iOS apps, such as Voice Memos, Calculator, and a native watchOS app store. watchOS 6.0 also introduced new features such as the noise app that allows one to measure ambient sound in decibels, menstrual tracking, and new watch faces. Other features include Siri being able to tell users what music they are listening to, activity trends, and a new UI framework for developers.[citation needed]

watchOS 7 was announced on June 22, 2020, at WWDC 2020, and released on September 16, 2020; new functions include sleep tracking, additional watch faces, handwashing detection, and new workouts such as dancing.[140]

watchOS 8 was announced on June 7, 2021, at WWDC 2021 and released on September 20, 2021. It replaces the Breathe app with a new Mindfulness app, and adds a Focus mode as well as a Portrait Watch Face, updates to the Messages and Home apps, Contacts and Find My apps, and a redesigned Photos app.[citation needed]

watchOS 9 was announced on June 6, 2022, and released on September 13, 2022. It enhances the Workout display with new views of metrics like Activity rings, Heart Rate Zones, Power, and Elevation. It also supports better sleep tracking and additional watch faces.[citation needed]

watchOS 10 was announced on June 5, 2023, at WWDC and released on September 18, 2023. It includes a major redesign of all stock watchOS apps, more detailed metrics available for cycling workouts, and new "Smart Stacks", stacks of widgets available from the clock.[citation needed]

watchOS 11 was announced on June 10, 2024, and released on September 16, 2024. It dropped support for the Apple Watch Series 4, Series 5, and 1st generation SE.

watchOS 26 was announced on June 9, 2025, and released on September 15, 2025.

Third-party apps

[edit]

In watchOS 1, third-party WatchKit applications run in the background on the iPhone as an application extension while a set of native user interface resources is installed on the Apple Watch.[141] Thus, watchOS apps must be bundled within their respective iOS app, and are synced to the watch either manually, or automatically upon installation of the phone app.[58]

With the release of watchOS 2, Apple made it mandatory for new watch apps to be developed with the watchOS 2 SDK from June 1, 2016, onwards; no third-party languages or SDKs can be used to develop apps.[142] This allowed for developers to create native apps that are run on the watch itself, thus improving the responsiveness of third-party apps.[citation needed]

In watchOS 5 and earlier, all watchOS apps are dependent apps – the watchOS app relies on an iOS companion app to function properly.[143] In watchOS 6 or later, developers can create completely independent watchOS apps, and no longer require an app to be installed on the paired iPhone. This was assisted by the introduction of a separate App Store on the Apple Watch itself.[144]

Reception

[edit]
An Apple Store opens its doors on the first day of sales of the Apple Watch.

Following the announcement, initial impressions from technology and watch industry observers were varied; the watch was praised by some for its "design, potential capabilities and eventual usefulness",[145] while others offered criticism of these same aspects.[145] Venture capitalist Marc Andreessen said he "can't wait" to try it,[146] and Steve Jobs' biographer Walter Isaacson described it as "extremely cool" and an example of future technology that is "much more embedded into our lives".[147] Evan Dashevsky of PC Magazine said it offered nothing new in terms of functionality compared to the Moto 360, except the customizable vibration notifications.[148] In November 2014, Apple Watch was listed by Time as one of the 25 Best Inventions of 2014.[149]

Trumpet player Chief Xian aTunde Adjuah wearing an Apple Watch

Initial reviews for the device have been generally positive with some caveats.[150] Reviewers praised the watch's potential ability to integrate into everyday life and the overall design of the product, but noted issues of speed and price. Many reviewers described the watch as functional and convenient, while also noting its failure to offer as much potential functionality as preceding smartphones. Farhad Manjoo of The New York Times mentioned the device's steep learning curve, stating it took him "three long, often confusing and frustrating days" to become accustomed to watchOS 1, but loved it thereafter.[151] Some reviewers also compared it to competing products, such as Android Wear devices, and claimed "The Smartwatch Finally Makes Sense".[152] Reviewers had mixed opinions on battery life though, with Geoffrey Fowler of The Wall Street Journal saying "the battery lives up to its all-day billing, but sometimes just barely,"[152] and others compared it to the Samsung Gear 2, which "strolls through three days of moderate usage."[153] Tim Bradshaw of the Financial Times used several applications over a period of days. He concluded that there is no "killer application" so far besides telling the time, which is the basic function of a wristwatch anyhow.[154]

When using the Apple Watch, some users have reported issues using the heart monitoring feature due to permanent skin conditions, including tattoos. The Watch uses photoplethysmography technology (PPG) that utilizes the green LEDs to measure heart rate.[155][156] To gauge a user's heart rate, the watch flashes green light from the LEDs at the skin and records the amount of this light that is absorbed by the red pigment of the blood.[157] Under certain circumstances, the skin may not allow for the light absorption to be read properly and thus provide inaccurate results.[155]

Some users have complained that the logo and text on the back of the Apple Watch Sport model, primarily the space gray version,[158] can be easily worn off.[159]

Sales

[edit]
Apple Watch Series 5

Financial analysts offered early sales estimates from a few million to as many as 5 million in the first year.[160] Time's Tim Bajarin summarized the breadth of reactions, writing that "there is not enough information yet to determine how this product will fare when it finally reaches the market next year".[145]

Owing to the inadequacy of materials, the Apple Watch's delivery was delayed from its initial pre-order release date of April 10, 2015.[161] As a result, only 22 percent of the pre-ordered Apple Watches were dispatched in the United States during the weekend after the release date.[162] It is estimated Apple received almost one million Apple Watch pre-orders in the United States during the initial six hours of the pre-order period on April 10, 2015, after which it sold out and further orders would start delivering in June.[163] A report later on by an analyst stated that Apple Watch was already a $10 billion business during its first year.[164]

Apple has not disclosed any sales figures for the Apple Watch.[165] An estimate by IDC states Apple shipped over 12 million units in 2015.[166] In late 2016, a veteran of the Swiss watch industry said Apple sold about 20 million watches and had a market share of about 50 percent.[167] Analysts estimate Apple sold 18 million watches in 2017, 31 million in 2019, and 34 million in 2020.[168] In 2021, analysts estimated there were 100 million units in use.[169]

In 2020, Apple sold more watches than the entire Swiss watch industry, which includes Swatch and TAG Heuer among others.[170]

Controversy

[edit]

In October 2024, the Apple Watch Series 10 received a sales ban in Indonesia, as an extension of the iPhone 16's sales ban.[130] The ban is due to Apple's failure to meet a 40% quota requirement for local component certification implemented by the Indonesian government, according to minister of industry Agus Gumiwang Kartasasmita.[130][171]

Intellectual property disputes

[edit]

In December 2019, Joseph Wiesel, a New York University cardiologist, sued Apple over allegations that the Apple Watch violates a patented method for detecting atrial fibrillation. Wiesel stated he had shared details of the patent with Apple in September 2017; the company refused to negotiate.[172]

Following Apple's announcement of the Series 7, an independent software development company filed a lawsuit against Apple alleging inappropriate copying of the software keyboard functionality from an app that Apple had previously rejected from its App Store.[173]

In October 2023, the United States International Trade Commission (ITC) ruled that Apple Watch products infringed patents for light-based pulse oximetry that are owned by medical technology company Masimo. The company alleged that Apple had approached Masimo with offers to acquire or otherwise partner with the company, and went on to poach engineers from Masimo to develop the infringing technology after it declined the offers. This ruling would allow the ITC to impose an import ban, provided it is not overruled by presidential veto power within a 60-day review period ending December 25. Apple denied the allegations, stating that it had solicited partnerships with multiple vendors, declined to work with Masimo because they were not in the consumer market, and accused Masimo of attempting to "use the ITC to keep a potentially lifesaving product from millions of US consumers while making way for their own watch that copies Apple."[174]

On December 18, 2023, Apple began to halt sales of Apple Watch Series 9 and Ultra 2 in the United States.[175] On December 27, 2023, the United States Court of Appeals for the Federal Circuit granted a stay on the import ban pending an appeal.[176] On January 12, 2024, Masimo disclosed that the ITC had approved modifications to the products that would remove the infringing technology.[177] Blood oxygen monitoring is not available on Apple Watch Series 9 and Ultra 2 models sold in the United States after January 18, 2024, designated by part numbers ending in "LW/A".[116]

On August 14, 2025, Apple announced the return of blood oxygen monitoring to models affected by the import ban. They were able to do this by "redesigning" the feature to use the sensors on the watch and process them on the paired iPhone. The results would then be viewable in the Health app.[178] That same day, they released iOS 18.6.1 and watchOS 11.6.1, returning the feature. On August 19, 2025, the same changes were brought to the iOS 26 and watchOS 26 codebase with developer beta 7.[179]

Comparison of models

[edit]

Life cycle

[edit]
Legend   Discontinued and unsupported   Discontinued and supported   Current   Upcoming
Model Announced Release Discontinued Latest release Support lifespan
OS Date OS Date
1st September 9, 2014 (2014-09-09) watchOS 1.0 April 24, 2015 (2015-04-24) September 7, 2016 (2016-09-07) watchOS 4.3.2[A] September 17, 2018 (2018-09-17) 3 years, 4 months
Series 1 September 7, 2016 (2016-09-07) watchOS 3.0 September 12, 2016 (2016-09-12) September 12, 2018 (2018-09-12) watchOS 6.3[B] September 15, 2020 (2020-09-15) 4 years
Series 2 September 16, 2016 (2016-09-16) September 12, 2017 (2017-09-12) 3 years, 11 months
Series 3 September 12, 2017 (2017-09-12) watchOS 4.0 September 22, 2017 (2017-09-22) September 7, 2022 (2022-09-07) watchOS 8.8.1[C] September 13, 2022 (2022-09-13) 4 years, 11 months
Series 4 September 12, 2018 (2018-09-12) watchOS 5.0 September 21, 2018 (2018-09-21) September 10, 2019 (2019-09-10) watchOS 10.6.1 September 16, 2024 (2024-09-16) 5 years, 11 months
Series 5 September 10, 2019 (2019-09-10) watchOS 6.0 September 20, 2019 (2019-09-20) September 15, 2020 (2020-09-15) 4 years, 11 months
SE (1st) September 15, 2020 (2020-09-15) watchOS 7.0 September 18, 2020 (2020-09-18) September 7, 2022 (2022-09-07) 3 years, 11 months
Series 6 September 14, 2021 (2021-09-14) Latest watchOS
watchOS 26
Supported 5 years, 1 month +
Series 7 September 14, 2021 (2021-09-14) watchOS 8.0 October 15, 2021 (2021-10-15) September 7, 2022 (2022-09-07) 4 years +
SE (2nd) September 7, 2022 (2022-09-07) watchOS 9.0 September 16, 2022 (2022-09-16) September 9, 2025 (2025-09-09) 3 years, 1 month +
Series 8 September 12, 2023 (2023-09-12) 3 years, 1 month +
Ultra (1st) September 23, 2022 (2022-09-23) 3 years, 1 month +
Series 9 September 12, 2023 (2023-09-12) watchOS 10.0 September 22, 2023 (2023-09-22) September 9, 2024 (2024-09-09) 2 years, 1 month +
Ultra 2 watchOS 10.0 September 22, 2023 (2023-09-22) September 9, 2025 (2025-09-09) 2 years, 1 month +
Series 10 September 9, 2024 (2024-09-09) watchOS 11.0 September 20, 2024 (2024-09-20) 1 year, 1 month +
SE 3 September 9, 2025 (2025-09-09) watchOS 26.0 September 19, 2025 (2025-09-19) In production 1 month +
Series 11 1 month +
Ultra 3 1 month +
  1. ^ watchOS 4.3.2 requires iOS version 11.4, but a higher version of iOS can still pair with a watchOS 4 watch.
  2. ^ watchOS 6.3 requires iOS version 13.5, but iOS 14 can still pair with a watchOS 6 watch.
  3. ^ watchOS 8.7.1 requires iOS version 15.6, but iOS 16 can still pair with a watchOS 8 watch.

Technical specifications

[edit]
Specification[180] 1st[181] Series 1[182] Series 2[183] Series 3[184] Series 4[185] Series 5[186] SE (1st)[187] Series 6[188] Series 7[189] SE (2nd)[190] Series 8[191] Ultra[192] Series 9[193] Ultra 2[194] Series 10[195] SE 3[196] Series 11[197] Ultra 3[198]
Resistance Water IPX7 splash resistant (up to 1 meter) ISO 22810:2010 water resistant (up to 50 meters) ISO 22810:2010 water resistant (up to 100 meters) ISO 22810:2010 water resistant (up to 50 meters) ISO 22810:2010 water resistant (up to 100 meters) ISO 22810:2010 water resistant (up to 50 meters) ISO 22810:2010 water resistant (up to 100 meters)
Dust IP6X dust resistant[199] IP6X dust resistant IP6X dust resistant
Connectivity Cellular (LTE / UMTS) No eSIM eSIM eSIM eSIM eSIM eSIM
Wireless networking Wi-Fi (802.11 b/g/n 2.4 GHz) Wi-Fi (802.11 b/g/n 2.4 GHz and 5 GHz) Wi-Fi (802.11 b/g/n 2.4 GHz) Wi-Fi (802.11 b/g/n 2.4 GHz and 5 GHz) Wi-Fi (802.11 b/g/n 2.4 GHz) Wi-Fi (802.11 b/g/n 2.4 GHz and 5 GHz)
Bluetooth Bluetooth 4.0 Bluetooth 4.2 Bluetooth 5.0 Bluetooth 5.3[200]
Ultra-wideband No U1 chip[201] No U1 chip Second-generation No Second-generation
Satellite navigation No GPS and GLONASS GPS, GLONASS, Galileo, and QZSS GPS, GLONASS, Galileo, QZSS, and BeiDou[109] GPS, GLONASS, Galileo, and QZSS GPS, GLONASS, Galileo, QZSS, and BeiDou
Sensors Optical heart sensor 1st generation 2nd generation 3rd generation 2nd generation 3rd generation 2nd generation 3rd generation
Electrical heart sensor (ECG/EKG) No Yes No Yes No Yes No Yes
Blood oxygen sensor No Yes No Yes Yes (Requires update for U.S. models)[202] No Yes
Temperature sensor No Yes
Accelerometer 16g 32g High-g[200]
Gyroscope Yes Improved High dynamic range
Ambient light sensor Yes
Altimeter No Yes Always on
Compass No Yes[186]
Input and display "Siri Speaks" and "Raise to Speak"[203] No Yes
Display type OLED Retina LTPO OLED Retina LTPO OLED Always-on Retina LTPO OLED Retina LTPO OLED Always-on Retina LTPO OLED Retina LTPO OLED Always-on Retina
Force Touch Yes No
Brightness (nits) 450 1000 2000 3000 2000 1000 2000 3000
Pixel density 326 ppi
Small diagonal size and resolution 38 mm: 1.337in
272×340 pixels[204]
40 mm: 1.549in
324×394 pixels[204][i]
41 mm: 1.691in
352×430 pixels[i]
40 mm: 1.549in
324×394 pixels[i]
41 mm: 1.691in
352×430 pixels[i]
1.936in
410×502 pixels[i]
41 mm: 1.691in
352×430 pixels[i]
1.936in
410×502 pixels[i]
42 mm: 1.765in
374×446 pixels[i]
40 mm: 1.549in
324×394 pixels[i]
42 mm: 1.765in
374×446 pixels[i]
1.984in
422×514 pixels[i]
Large diagonal size and resolution 42 mm: 1.533in
312×390 pixels[204]
44 mm: 1.757in
368×448 pixels[204][i]
45 mm: 1.901in
396×484 pixels[i]
44 mm: 1.757in
368×448 pixels[i]
45 mm: 1.901in
396×484 pixels[i]
45 mm: 1.901in
396×484 pixels[i]
46 mm: 1.960in
416×496 pixels[i]
44 mm: 1.757in
368×448 pixels[i]
46 mm: 1.960in
416×496 pixels[i]
Chipset System in Package Apple S1 Apple S1P Apple S2 Apple S3 Apple S4 Apple S5 Apple S6 Apple S7 Apple S8 Apple S9 Apple S10
CPU 520 MHz 32-bit single-core[205] 520 MHz 32-bit dual-core[206] 32-bit dual-core 64-bit dual-core Tempest 64-bit dual-core Thunder 64-bit dual-core Sawtooth
Storage GB[205] GPS: 8 GB
GPS + Cellular: 16 GB
16 GB 32 GB 64 GB
RAM 512 MB DRAM[205][207] 768 MB DRAM[208] 1 GB DRAM[209][210]
OS Initial watchOS 1.0 watchOS 3.0 watchOS 4.0 watchOS 5.0 watchOS 6.0 watchOS 7.0 watchOS 8.0 watchOS 9.0 watchOS 10.0 watchOS 11.0 watchOS 26.0
Latest watchOS 4.3.2 watchOS 6.3 watchOS 8.8.1 watchOS 10.6.1 watchOS 26.0.2
Minimum devices
and iOS
iPhone 5
iOS 8.2
iPhone 5
iOS 10[211]
GPS:
iPhone 5S
iOS 11

GPS + Cellular:
iPhone 6
iOS 11
GPS:
iPhone 5S
iOS 12

GPS + Cellular:
iPhone 6
iOS 12
iPhone 6s
iOS 13
iPhone 6s
iOS 14
iPhone 6s
iOS 15
iPhone 8
iOS 16
iPhone XS
iOS 17
iPhone XS
iOS 18
iPhone 11
iOS 26
Battery Small case capacity 205 mA·h, 3.8 V, 0.78 W·h[212] 273 mA·h, 3.77 V, 1.03 W·h[213] GPS: 262 mA·h, 3.81 V, 1.00 W·h[214] 224.9 mA·h, 3.81 V, 0.858 W·h[215] 245 mA·h, 3.85 V, 0.944 W·h[215][216] 265.9 mA·h, 3.85 V, 1.024 W·h[217] 284.2 mA·h, 3.85 V, 1.094 W·h[218] GPS: 209 mA·h, 3.86 V, 0.807 W·h 284 mA·h, 3.85 V, 1.094 W·h 542 mA·h, 3.86 V, 2.094 W·h[219] 282 mA·h, 3.87 V, 1.091 W·h 564 mA·h, 3.86 V, 2.178 W·h 290 mA·h, 3.86 V, 1.118 W·h 1.017 W·h 1.245 W·h 599 mA·h, 3.86 V, 2.313 W·h
GPS + Cellular: 279 mA·h, 3.82 V, 1.07 W·h[220] GPS + Cellular: 245 mA·h, 3.85 V, 0.944 W·h
Large case capacity 246 mA·h, 3.78 V, 0.93 W·h[212] 334 mA·h, 3.8 V, 1.27 W·h[221] GPS: 342 mA·h, 3.82 V, 1.31 W·h[222] 291.8 mA·h, 3.81 V, 1.113 W·h[223] 296 mA·h, 3.814 V, 1.129 W·h[224][225] 303.8 mA·h, 3.85 V, 1.17 W·h[217] 308.8 mA·h, 3.85 V, 1.189 W·h[218] 296 mA·h, 3.814 V, 1.129 W·h 308 mA·h, 3.86 V, 1.19 W·h 308 mA·h, 3.86 V, 1.19 W·h 327 mA·h, 3.87 V, 1.266 W·h 1.276 W·h 1.403 W·h
GPS + Cellular: 352 mA·h, 3.82 V, 1.34 W·h[226]
Charge times ~1.5 hours to 80%
~2 hours to 100%[227][228]
~1.5 hours to 80%
~2.5 hours to 100%[227]
~1 hour to 80%
~1.5 hours to 100%[229]
~45 minutes to 80%
~75 minutes to 100%[230]
~1.5 hours to 80%
~2.5 hours to 100%
~45 minutes to 80%
~75 minutes to 100%
~1 hour to 80%
~1.5 hours to 100%
~45 minutes to 80% ~1 hour to 80% ~30 minutes to 80% ~45 minutes to 80% ~30 minutes to 80% ~45 minutes to 80%
Battery life 24h 18h 36h 18h 36h 18h 24h 42h
Greenhouse gas emissions 50 kg CO2e[231] 20 kg CO2e[232] 30 kg CO2e[233] GPS: 28 kg CO2e[234]
GPS + Cellular: 36 kg CO2e[235]
GPS: 38 kg CO2e[236]
GPS + Cellular: 39 kg CO2e[237]
40 kg CO2e[238] 35 kg CO2e[239] 36 kg CO2e[240] 34 kg CO2e[241] 31 kg CO2e[242] 33 kg CO2e[243] 56 kg CO2e[244] 29 kg CO2e[245] 12 kg CO2e[246] 8.3 kg CO2e[247] 8.2 kg CO2e[248] 8.1 kg CO2e[249] 11 kg CO2e[250]
Dates Introduced September 9, 2014 September 7, 2016 September 12, 2017 September 12, 2018 September 10, 2019 September 15, 2020 September 14, 2021 September 7, 2022 September 12, 2023 September 9, 2024 September 9, 2025
Released April 24, 2015 September 12, 2016 September 16, 2016 September 22, 2017 September 21, 2018 September 25, 2019 September 18, 2020 October 15, 2021 September 16, 2022 September 23, 2022 September 22, 2023 September 20, 2024 September 19, 2025
Discontinued September 7, 2016 September 12, 2018 September 12, 2017 September 7, 2022 September 10, 2019 September 15, 2020 September 7, 2022 October 8, 2021[251] September 7, 2022 September 9, 2025 September 12, 2023 September 9, 2024 September 9, 2025 In production
Unsupported September 17, 2018 December 14, 2020 September 12, 2022 September 16, 2024 Current
Model numbers[252] A1553 (38 mm)
A1554 (42 mm)
A1802 (38 mm)
A1803 (42 mm)
A1757 (38 mm)
A1758 (42 mm)

Edition:
A1816 (38 mm)
A1817 (42 mm)
GPS:
A1858 (38 mm)
A1859 (42 mm)

GPS + Cellular:
Americas:
A1860 (38 mm)
A1861 (42 mm)

Europe and Asia Pacific:
A1889 (38 mm)
A1891 (42 mm)

China mainland:
A1890 (38 mm)
A1892 (42 mm)
GPS:
A1977 (40 mm)
A1978 (44 mm)

GPS + Cellular:
North America:
A1975 (40 mm)
A1976 (44 mm)

Europe, Asia Pacific, and China mainland:
A2007 (40 mm)
A2008 (44 mm)
GPS:
A2092 (40 mm)
A2093 (44 mm)

GPS + Cellular:
North America:
A2094 (40 mm)
A2095 (44 mm)

Europe, Asia Pacific, and China mainland:
A2156 (40 mm)
A2157 (44 mm)
GPS:
A2351 (40 mm)
A2352 (44 mm)

GPS + Cellular:
North America:
A2353 (40 mm)
A2354 (44 mm)

Europe, Asia Pacific, and China mainland:
A2355 (40 mm)
A2356 (44 mm)
GPS:
A2291 (40 mm)
A2292 (44 mm)

GPS + Cellular:
North America:
A2293 (40 mm)
A2294 (44 mm)

Europe, Asia Pacific, and China mainland:
A2375 (40 mm)
A2376 (44 mm)
GPS:
A2473 (41 mm)
A2474 (45 mm)

GPS + Cellular:
North America:
A2475 (41 mm)
A2477 (45 mm)

Europe, Asia Pacific, and China mainland:
A2476 (41 mm)
A2478 (45 mm)
GPS:
A2722 (40 mm)
A2723 (44 mm)

GPS + Cellular:
North America:
A2726 (40 mm)
A2727 (44 mm)

Europe and Asia Pacific:
A2725 (40 mm)
A2724 (44 mm)
China mainland:
A2855 (40 mm)
A2856 (44 mm)
GPS:
A2770 (41 mm)
A2771 (45 mm)

GPS + Cellular:
North America:
A2772 (41 mm)
A2774 (45 mm)

Europe and Asia Pacific:
A2773 (41 mm)
A2775 (45 mm)
China mainland:
A2857 (41 mm)
A2858 (45 mm)
North America:
A2622
Europe and Asia Pacific:
A2684

China mainland:
A2859
GPS:
A2978 (41 mm)
A2980 (45 mm)

GPS + Cellular:
North America, Europe and Asia Pacific:
A2982 (41 mm)
A2984 (45 mm)

China mainland:
A2983 (41 mm)
A2985 (45 mm)
North America, Europe, and Asia Pacific:
A2986

China mainland:
A2987
GPS:
North America, Europe, Asia Pacific:
A2997 (42 mm)
A2999 (46 mm)

China mainland, Indonesia:
A2998 (42 mm)
A3000 (46 mm)

GPS + Cellular:
North America, Europe, Asia Pacific:
A3001 (42 mm)
A3003 (46 mm)

China mainland, Indonesia:
A3002 (42 mm) A3006 (46 mm)
GPS:
North America, Europe, Asia Pacific:
A3324 (40 mm)
A3325 (42 mm)

China mainland:
A3391 (40 mm)
A3392 (44 mm)

GPS + Cellular:
North America, Europe, Asia Pacific:
A3326 (40 mm)
A3328 (44 mm)

China mainland:
A3327 (40 mm) A3329 (44 mm)
GPS:
North America, Europe, Asia Pacific:
A3331 (42 mm)
A3333 (46 mm)

China mainland:
A3450 (42 mm)
A3451 (46 mm)

GPS + Cellular:
North America, Europe, Asia Pacific:
A3335 (42 mm)
A3337 (46 mm)

China mainland:
A3452 (42 mm) A3453 (46 mm)
North America, Europe, and Asia Pacific:
A3281

China mainland:
A3282
Starting price (US)
small / large
Base model (Aluminum) $349 / $399[253] $269[254] $369[254] GPS: $329 / 359
GPS + Cellular: $399[255]
GPS: $399 / $429
GPS + Cellular: $499 / $529[256][257][258]
GPS: $279 / $309
GPS + Cellular: $329 / $359[259]
GPS: $399 / $429
GPS + Cellular: $499 / $529
GPS: $249 / $279
GPS + Cellular: $279 / $329
GPS: $399 / $429
GPS + Cellular: $499 / $529
GPS: $399 / $429
GPS + Cellular: $499 / $529
GPS: $399 / $429
GPS + Cellular: $499 / $529
GPS: $249 / $279
GPS + Cellular: $279 / $329
GPS: $399 / $429
GPS + Cellular: $499 / $529
Stainless steel $549 / $599[253] $549 $749 / $799[260] $699 / $749[256][258] $699 / $749 $699 / $749 $699 / $749
Titanium $799 $799 $699 / $749 $699 / $749 $799
Nike+ $369[254] GPS: $329[255] $399[257][258] $279 $399
Hermès $1,149[254] $1,149[255] $1,249[257][258] $1,229 $1,229 $1,249 / $1,299 $1,399 $1,249 / $1,299 $1,249 / $1,299 $1,399
Edition $10,000 / $12,000[261] $1,249 / $1,299[262] $1,299 / $1,349[260] $799 (Titanium)[258]
$1,299 (Ceramic)[263]
$799

Physical specifications

[edit]
Series Small Large
Aluminium Stainless Steel Titanium Edition[ii] Image Aluminium Stainless Steel Titanium Edition[iii] Image
1st[264][181][265] H 38.6 mm (1.52 in) 42.0 mm (1.65 in)
W 33.3 mm (1.31 in) 35.9 mm (1.41 in)
D 10.5 mm (0.41 in) 10.5 mm (0.41 in)
Weight 25 g (0.88 oz) 40 g (1.4 oz) 54–55 g (1.9–1.9 oz) 30 g (1.1 oz) 50 g (1.8 oz) 67–69 g (2.4–2.4 oz)
Series 1[182] H 38.6 mm (1.52 in) 42.5 mm (1.67 in)
W 33.3 mm (1.31 in) 36.4 mm (1.43 in)
D 10.5 mm (0.41 in) 10.5 mm (0.41 in)
Weight 25 g (0.88 oz) 30 g (1.1 oz)
Series 2[183] H 38.6 mm (1.52 in) 39.2 mm (1.54 in) 42.5 mm (1.67 in) 42.6 mm (1.68 in)
W 33.3 mm (1.31 in) 34.0 mm (1.34 in) 36.4 mm (1.43 in) 36.5 mm (1.44 in)
D 11.4 mm (0.45 in) 11.8 mm (0.46 in) 11.4 mm (0.45 in) 11.8 mm (0.46 in)
Weight 28.2 g (0.99 oz) 41.9 g (1.48 oz) 39.6 g (1.40 oz) 34.2 g (1.21 oz) 52.4 g (1.85 oz) 45.6 g (1.61 oz)
Series 3[184] H 38.6 mm (1.52 in) 39.2 mm (1.54 in) 42.5 mm (1.67 in) 42.6 mm (1.68 in)
W 33.3 mm (1.31 in) 34.0 mm (1.34 in) 36.4 mm (1.43 in) 36.5 mm (1.44 in)
D 11.4 mm (0.45 in) 11.8 mm (0.46 in) 11.4 mm (0.45 in) 11.8 mm (0.46 in)
Weight 26.7–28.7 g (0.94–1.01 oz) 42.4 g (1.50 oz) 40.1 g (1.41 oz) 32.3–34.9 g (1.14–1.23 oz) 52.8 g (1.86 oz) 46.4 g (1.64 oz)
Series 4[185] H 40 mm (1.6 in) 44 mm (1.7 in)
W 34 mm (1.3 in) 38 mm (1.5 in)
D 10.7 mm (0.42 in) 10.7 mm (0.42 in)
Weight 30.1 g (1.06 oz) 39.8 g (1.40 oz) 36.7 g (1.29 oz) 47.9 g (1.69 oz)
Series 5[186] H 40 mm (1.6 in) 44 mm (1.7 in)
W 34 mm (1.3 in) 38 mm (1.5 in)
D 10.74 mm (0.423 in) 10.74 mm (0.423 in)
Weight 30.8 g (1.09 oz) 40.6 g (1.43 oz) 35.1 / 39.7 g (1.24 / 1.40 oz) Ti/C 36.5 g (1.29 oz) 47.8 g (1.69 oz) 41.7 / 46.7 g (1.47 / 1.65 oz) Ti/C
SE (1st)[187] H 40 mm (1.6 in) 44 mm (1.7 in)
W 34 mm (1.3 in) 38 mm (1.5 in)
D 10.7 mm (0.42 in) 10.7 mm (0.42 in)
Weight 30.49–30.68 g (1.076–1.082 oz) 36.20–36.36 g (1.277–1.283 oz)
Series 6[188] H 40 mm (1.6 in) 44 mm (1.7 in)
W 34 mm (1.3 in) 38 mm (1.5 in)
D 10.7 mm (0.42 in) 10.7 mm (0.42 in)
Weight 30.5 g (1.08 oz) 39.7 g (1.40 oz) 34.6 g (1.22 oz) 36.5 g (1.29 oz) 47.1 g (1.66 oz) 41.3 g (1.46 oz)
Series 7[189] H 41 mm (1.6 in) 45 mm (1.8 in)
W 35 mm (1.4 in) 38 mm (1.5 in)
D 10.74 mm (0.423 in) 10.74 mm (0.423 in)
Weight 32.0 g (1.13 oz) 42.3 g (1.49 oz) 37 g (1.3 oz) 38.8 g (1.37 oz) 51.5 g (1.82 oz) 45.1 g (1.59 oz)
SE (2nd)[190] H 40 mm (1.6 in) 44 mm (1.7 in)
W 34 mm (1.3 in) 38 mm (1.5 in)
D 10.7 mm (0.42 in) 10.7 mm (0.42 in)
Weight 26.4–27.8 g (0.93–0.98 oz) 32.9–33.0 g (1.16–1.16 oz)
Series 8[191] H 41 mm (1.6 in) 45 mm (1.8 in)
W 35 mm (1.4 in) 38 mm (1.5 in)
D 10.74 mm (0.423 in) 10.74 mm (0.423 in)
Weight 31.9–32.2 g (1.13–1.14 oz) 42.3 g (1.49 oz) 38.8–39.1 g (1.37–1.38 oz) 51.5 g (1.82 oz)
Ultra[192] H 49 mm (1.9 in)
W 44 mm (1.7 in)
D 14.4 mm (0.57 in)
Weight 61.3 g (2.16 oz)
Series 9[193] H 41 mm (1.6 in) 45 mm (1.8 in)
W 35 mm (1.4 in) 38 mm (1.5 in)
D 10.7 mm (0.42 in) 10.7 mm (0.42 in)
Weight 31.9–32.1 g (1.13–1.13 oz) 42.3 g (1.49 oz) 38.7–39 g (1.37–1.38 oz) 51.5 g (1.82 oz)
Ultra 2[194] H 49 mm (1.9 in)
W 44 mm (1.7 in)
D 14.4 mm (0.57 in)
Weight 61.4–61.8 g (2.17–2.18 oz)
Series 10[195] H 42 mm (1.7 in) 42 mm (1.7 in) 46 mm (1.8 in) 46 mm (1.8 in)
W 36 mm (1.4 in) 36 mm (1.4 in) 39 mm (1.5 in) 39 mm (1.5 in)
D 9.7 mm (0.38 in) 9.7 mm (0.38 in) 9.7 mm (0.38 in) 9.7 mm (0.38 in)
Weight 29.3–30 g (1.03–1.06 oz) 34.4 g (1.21 oz) 35.3–36.4 g (1.25–1.28 oz) 41.7 g (1.47 oz)
SE 3[196] H 40 mm (1.6 in) 44 mm (1.7 in)
W 34 mm (1.3 in) 38 mm (1.5 in)
D 10.7 mm (0.42 in) 10.7 mm (0.42 in)
Weight 26.3–26.4 g (0.93–0.93 oz) 32.9–33.0 g (1.16–1.16 oz)
Series 11[197] H 42 mm (1.7 in) 42 mm (1.7 in) 46 mm (1.8 in) 46 mm (1.8 in)
W 36 mm (1.4 in) 36 mm (1.4 in) 39 mm (1.5 in) 39 mm (1.5 in)
D 9.7 mm (0.38 in) 9.7 mm (0.38 in) 9.7 mm (0.38 in) 9.7 mm (0.38 in)
Weight 29.7–30.3 g (1.05–1.07 oz) 34.6 g (1.22 oz) 36.9–37.8 g (1.30–1.33 oz) 43.1 g (1.52 oz)
Ultra 3[198] H 49 mm (1.9 in)
W 44 mm (1.7 in)
D 14.4 mm (0.57 in)
Weight 61.6–61.8 g (2.17–2.18 oz)
  1. ^ a b c d e f g h i j k l m n o p q r s Viewable area reduced by rounded corners
  2. ^ 18K gold (1st gen), Ceramic (Series 2/3/5), or Titanium (Series 5/6/7) body. Apple dropped the "Edition" moniker with the release of Series 8.
  3. ^ 18K gold (1st gen), Ceramic (Series 2/3/5), or Titanium (Series 5/6/7) body. Apple dropped the "Edition" moniker with the release of Series 8.

Collections and materials

[edit]
Series[252] Watch Nike+ Hermès Edition
1st Body "Sport": Aluminum
(Silver, Space Gray, Rose Gold, Gold)[264]
Stainless steel
(Polished or Space Black)[181]
18K Gold
(Rose or Yellow)[265]
Crystal "Sport": Ion-X[264] Sapphire[181] Sapphire[265]
Back "Sport": Composite[264] Ceramic[181] Ceramic[265]
Series 1 Body Aluminum
(Space Gray, Gold, Rose Gold, Silver)
Crystal Ion-X
Back Composite
Series 2 Body Aluminum
(Space Gray, Gold, Rose Gold, Silver)
Stainless steel
(Space Black, Polished)
Aluminum
(Space Gray, Silver)
Stainless steel
(Polished)
Ceramic
(White)
Crystal Ion-X Sapphire Ion-X Sapphire
Back Ceramic Ceramic Ceramic with Hermès logo Ceramic
Series 3 Body Aluminum
(Space Gray, Gold, Silver)
Stainless steel
(Space Black, Polished)
Aluminum
(Space Gray, Silver)
Stainless steel
(Polished)
Ceramic
(White, Gray)
Crystal Ion-X Sapphire Ion-X Sapphire
Back Composite (GPS) Ceramic Composite (GPS) with Nike logo Ceramic with Hermès logo Ceramic
Ceramic (GPS+LTE) Ceramic (GPS+LTE) with Nike Logo
Series 4 Body Aluminum
(Space Gray, Gold, Silver)
Stainless steel
(Polished, Space Black, Gold)
Aluminum
(Space Gray, Silver)
Stainless steel
(Polished)
Crystal Ion-X Sapphire Ion-X Sapphire
Back Ceramic Ceramic with Nike logo Ceramic with Hermès logo
Series 5 Body Aluminum
(Space Gray, Gold, Silver)
Stainless steel
(Polished, Space Black, Gold)
Aluminum
(Space Gray, Silver)
Stainless steel
(Polished, Space Black)
Titanium
(Dark, Light)
Ceramic
(White)
Crystal Ion-X Sapphire Ion-X Sapphire
Back Ceramic Ceramic with Nike logo Ceramic with Hermès logo Ceramic
SE (1st) Body Aluminum
(Space Gray, Gold, Silver)
Aluminum
(Space Gray, Silver)
Crystal Ion-X Ion-X
Back Ceramic Ceramic with Nike logo
Series 6 Body Aluminum
(Space Gray, Gold, Silver, Red, Blue)
Stainless steel
(Silver, Graphite, Gold)
Aluminum
(Space Gray, Silver)
Stainless steel
(Silver, Space Black)
Titanium
(Natural, Space Black)
Crystal Ion-X Sapphire Ion-X Sapphire
Back Ceramic Ceramic with Nike logo Ceramic with Hermès logo Ceramic
Series 7 Body Aluminum
(Midnight, Starlight, Green, Blue, (PRODUCT)RED)
Stainless steel
(Silver, Graphite, Gold)
Aluminum
(Midnight, Starlight)
Stainless steel
(Silver, Space Black)
Titanium
(Natural, Space Black)
Crystal Ion-X Sapphire Ion-X Sapphire
Back Ceramic Ceramic with Nike logo Ceramic with Hermès logo Ceramic
SE (2nd) Body Aluminum
(Midnight, Starlight, Silver)
Crystal Ion-X
Back Composite
Series 8 Body Aluminum
(Midnight, Starlight, Silver, (PRODUCT)RED)
Stainless steel
(Silver, Graphite, Gold)
Stainless steel
(Silver, Space Black)
Crystal Ion-X Sapphire Sapphire
Back Ceramic Ceramic with Hermès logo
Ultra Body Titanium
Crystal Sapphire
Back Ceramic
Series 9 Body Aluminum

(Midnight, Starlight, Silver, Pink, (PRODUCT)RED)

Stainless steel

(Silver, Graphite, Gold)

Stainless steel
(Silver, Space Black)
Crystal Ion-X Sapphire Sapphire
Back Ceramic Ceramic with Hermès logo
Ultra 2 Body Titanium

(Natural, Black)

Titanium

(Natural)

Crystal Sapphire Sapphire
Back Ceramic Ceramic
Series 10 Body Aluminum

(Jet Black, Rose Gold, Silver)

Titanium

(Natural, Slate, Gold)

Titanium

(Silver)

Crystal Ion-X Sapphire Sapphire
Back Aluminum Titanium Titanium with Hermès logo
SE 3 Body Aluminum
(Midnight, Starlight)
Crystal Ion-X
Back Composite
Series 11 Body Aluminum
(Jet Black, Rose Gold, Silver, Space Gray)
Titanium
(Natural, Slate, Gold)
Titanium
(Silver)
Crystal Ion-X Sapphire Sapphire
Back Aluminum Titanium Titanium with Hermès logo
Ultra 3 Body Titanium
(Natural, Black)
Titanium
(Natural)
Crystal Sapphire Sapphire
Back Ceramic Ceramic
  • 1st generation only: Apple Watch was sold as "Apple Watch Sport" (Aluminum body) and "Apple Watch" (Stainless steel body). Later generations sold both body materials as "Apple Watch".

See also

[edit]

Notes

[edit]

References

[edit]
[edit]
Revisions and contributorsEdit on WikipediaRead on Wikipedia
from Grokipedia
<!--Infobox Start [Smartwatches]--> | name = Apple Watch | developer = Apple Inc. | manufacturer = Apple Inc. | type = smartwatch | announced = September 9, 2014 | release_date = April 24, 2015 | lifespan = 2015–present | status = In production | operating_system = watchOS | system_on_chip = S-series | latest_model = Series 11 | latest_release_date = September 2025 | display_type = OLED | display_size = 40–49 mm | connectivity = Bluetooth 5.3 | Wi-Fi 802.11n | optional 5G/LTE | second-generation Ultra Wideband | sensors = heart rate monitor | ECG | temperature sensor | altimeter | GPS | blood oxygen sensor | battery_type = rechargeable lithium-ion | battery_life = up to 36 hours | water_resistance = 50 meters (standard models), 100 meters (Ultra models) | compatibility = iPhone | introductory_price = $349 | starting_price = $249 | website = https://www.apple.com/apple-watch/ | country_of_origin = United States <!--Infobox End--> The Apple Watch is a line of smartwatches designed, developed, and marketed by Apple Inc., integrating touchscreen displays, sensors for health and fitness monitoring, notifications, and seamless connectivity with a paired iPhone primarily via Bluetooth, with a typical range of approximately 10 meters (33 feet) that can vary based on environmental factors like interference; connectivity can extend beyond Bluetooth range if both devices are on the same Wi-Fi network, and cellular models can operate independently without the iPhone. GPS + Cellular models can share their location via Find My even when the paired iPhone is left at home, using the watch's built-in GPS and cellular connection to report its location to iCloud independently, provided cellular service is active and the watch is signed in to iCloud. Cellular service requires an active plan from a supported carrier, as Apple does not provide a fixed monthly cost; users should contact their carrier for pricing details. In the United States, major carriers typically charge around $10 per month for Apple Watch cellular add-ons, though rates vary by provider and plan. The Apple Watch is not officially compatible with Android phones and requires an iPhone for initial setup, full functionality, software updates, and access to most features. Apple has no announced plans to support Android compatibility as of 2026 or in future models. Reports from Apple's antitrust proceedings indicate that the company explored Android support for three years but abandoned the effort due to technical limitations and strategic decisions to maintain ecosystem integration. Limited workarounds exist, such as initial setup with an iPhone followed by use of a cellular model for basic functions like calls, messages, and fitness tracking, but these sacrifice key features including Apple Pay, Siri, reliable messaging, and full data syncing. Announced on September 9, 2014, and first released on April 24, 2015, it features a rectangular OLED display, Digital Crown for precise navigation, and modular watch faces customizable via software updates. Successive models, released annually as Series iterations alongside variants like Ultra for rugged use and SE for entry-level access, have advanced hardware including GPS, altimeters, and processors like the S-series chips, enabling features such as GPS tracking, wrist sensing, and up to 36-hour battery life in premium editions. By 2025, the lineup includes Series 11 with notifications and enhanced sleep tracking, running for app support and Apple Intelligence integration. The device has achieved dominance in the smartwatch category, shipping tens of millions of units annually and maintaining a leading global through superior integration with Apple's ecosystem, though facing increasing competition from Android-based rivals. Key health innovations, including FDA-cleared ECG functionality and irregular heart rhythm alerts introduced in Series 4 onward, have positioned it as a tool for early detection of conditions like , despite documented risks of false positives prompting unnecessary medical visits. Patent disputes, notably over technology with , have led to U.S. import restrictions on recent models, resolved via design workarounds.

History

Development

The Apple Watch project originated in late 2011, shortly after ' death on October 5, 2011, when Apple's chief design officer began exploring concepts for a wrist-worn device. Ive, inspired by the need to extend iPhone capabilities into personal wearables, assembled a core team of designers including Alan Dye to prototype revolutionary form factors that prioritized , , and integration with health monitoring features. Formal development accelerated in early 2012, following the launch, with Ive confirming that substantive discussions on the project—initially codenamed iWatch—did not commence until then. The effort expanded to involve hundreds of engineers and designers tackling technical hurdles such as compact power-efficient processors, flexible displays, and haptic feedback systems tailored for interaction. Ive's Group led the aesthetic evolution, iterating through numerous prototypes to achieve a sapphire crystal face and customizable bands while ensuring for skin contact. Key innovations emerged from cross-disciplinary collaboration, including the development of the single-chip system-on-a-chip, which integrated CPU, GPU, memory, and sensors into a diminutive package measuring approximately 14 mm by 14 mm to fit the watch's constrained form factor. Battery life optimization proved particularly challenging, requiring custom algorithms to manage power draw from always-on displays and continuous biometric tracking like monitoring via optical sensors. By mid-2013, the project had progressed to refined mockups, incorporating wireless charging coils and Taptic Engine for subtle vibrations, setting the stage for software development of .

Announcement and Initial Release

The Apple Watch was publicly announced on September 9, 2014, during an Apple special event at the Flint Center in , where CEO introduced it as "Apple's most personal device ever." The device featured a rectangular with rounded corners, a digital crown for navigation, and capabilities for messaging, calls, and app integration via pairing with an . Announced alongside the and Plus, the Watch was positioned as an extension of Apple's ecosystem, with initial models offered in 38 mm and 42 mm sizes across aluminum, , and 18-karat gold editions 18-karat gold edition priced from $349 to $17,000. Pre-orders for the Apple Watch commenced on April 10, 2015, with retail availability beginning April 24, 2015, initially in eight countries including the , , and . On the first day of pre-orders, approximately 957,000 units were ordered in the alone, according to analysis of online purchase data, surpassing initial launch-day figures in some metrics but falling short of broader wearable market expectations for the year. Analysts estimated first-year sales at around 12 million units, generating approximately $6 billion in revenue at an average price of $500 per device. The launch emphasized in-store try-on experiences, with online sales dominating initial distribution due to high demand and limited stock.

Generational Evolution

The Apple Watch originated with the first-generation model, released on April 24, 2015, equipped with the single-core S1 system-in-a-package (SiP) processor, which managed core functions like notifications, basic fitness tracking via an optical sensor, and timekeeping but suffered from performance lag due to its 520 MHz speed and handling display driving, connectivity, and motion . This initial architecture laid the foundation for wearable computing but required offloading complex tasks to paired iPhones, limiting standalone utility. Early iterations addressed speed and autonomy: the Series 1 (September 2016) upgraded to the dual-core S1P for approximately 50% faster performance while retaining the original display sizes of 38 mm and 42 mm; the Series 2 (September 2016) introduced the S2 dual-core SiP with built-in GPS for independent location tracking and 50-meter water resistance, enabling swim-proof operation without compromising the 18-hour battery life benchmark established from launch. The Series 3 (September 2017) added the S3 dual-core processor with a W2 chip supporting optional LTE connectivity for cellular independence, alongside a for accurate elevation data during activities like . A pivotal shift occurred with Series 4 (September 2018), which debuted the 64-bit S4 dual-core SiP—clocked at 2x the GPU speed of prior models—for enhanced graphics and app responsiveness, paired with a redesigned expanding display area by 30% to 40 mm and 44 mm sizes and introducing electrical heart sensors for electrocardiogram (ECG) readings to detect . Fall detection via and data was also added, alerting emergency services if the wearer remained immobile post-impact. Subsequent models built on this: Series 5 (2019) integrated the S5 SiP with a always-on LTPO OLED for glanceable information without wrist-raising; Series 6 (2020) featured the S6 SiP with U1 chip for precise finding, blood (SpO2) monitoring via red and LEDs, and brighter always-on screens. Refinements continued with larger, more durable designs: Series 7 (2021) employed the S7 SiP in 41 mm and 45 mm cases with IP6X dust resistance and 33% faster charging; Series 8 (2022) added the S8 SiP, skin temperature sensing for cycle tracking, and crash detection using expanded sensor fusion. The S9 SiP in Series 9 (2023) doubled neural engine performance for on-device Siri processing and introduced a double-tap gesture via neural network interpretation of finger motion, alongside a 2000-nit display peak. Series 10 (2024) advanced to the S10 SiP—a smaller die variant supporting wide-angle OLED for better viewing angles—with a thinner 9.7 mm chassis, 40% larger display area in 42 mm and 46 mm sizes, and sleep apnea notifications derived from breathing disturbance analysis over 30 days. For the first time in 2025, the Series 11 retained the S10 SiP without a new chip generation, emphasizing software optimizations and 5G enhancements over hardware leaps.
GenerationKey Processor UpgradeDisplay/Design EvolutionHealth/Feature Additions
Series 0 (2015)S1 single-core38/42 mm Retina OLEDOptical HR, accelerometer
Series 1-3 (2016-2017)S1P/S2/S3 dual-coreSame sizes; GPS (S2), LTE (S3)Altimeter (S3)
Series 4-6 (2018-2020)S4-S6 64-bit dual-coreLarger 40/44 mm; always-on (S5), SpO2 (S6)ECG, fall detection (S4); U1 chip (S6)
Series 7-9 (2021-2023)S7-S9 with neural focus41/45 mm; dust resistance (S7), brighter (S9)Temp sensor, crash detection (S8); double-tap (S9)
Series 10+ (2024-)S10 (reused in 2025)Thinner, wide-angle OLED, larger areaSleep apnea detection
This progression reflects Apple's strategy of annual hardware increments prioritizing sensor accuracy—validated against clinical standards for features like ECG FDA clearance—and battery efficiency, with SiP integration reducing power draw from early models' 20-30% idle loss to under 1% per hour in recent LTPO implementations, though critics note diminishing returns in core fitness metrics amid maturing smartwatch markets.

Models

First Generation

The first-generation Apple Watch was announced on September 9, 2014, alongside the and iPhone 6 Plus, and released on April 24, 2015, initially in select countries before wider availability. It was available in three variants: the standard model in , the Sport model in aluminum, and the Edition model in 18-karat , with case sizes of 38 mm and 42 mm. The device featured a rectangular with capability for distinguishing between light and firm presses, protected by Ion-X strengthened glass in aluminum models or crystal in and versions. Powered by the system-in-package (SiP), which integrated over 30 components including a single-core 32-bit ARMv7-based APL0778 processor, PowerVR SGX543 GPU, 512 MB RAM, and 8 GB storage, the watch handled basic computations locally but relied heavily on a paired for advanced processing and internet connectivity via 4.0 or Wi-Fi (802.11b/g/n). Sensors included an optical , accelerometer for activity tracking, and ambient light sensor, but lacked a and built-in GPS, requiring connection to an for location services. The watch ran watchOS 1, supporting notifications, calls, emails, voice commands, and fitness tracking for steps, calories, and basic monitoring, with customizable watch faces and interchangeable bands. Battery capacity varied by size: 205 mAh for the 38 mm model and 250 mAh for the 42 mm, providing up to 18 hours of normal use before requiring magnetic , which took about 2.5 hours for a full charge. The device was rated IPX7 water-resistant for splashes and brief submersion up to 1 meter, but not for . Priced starting at $349 for the model, it sold over 4.2 million units in its first full quarter, establishing Apple as a leader in wearables despite criticisms of limited standalone functionality and short battery life relative to competitors.

Series 1 and 2

The Apple Watch Series 1 and Series 2 were announced on September 7, 2016, alongside the , and released on September 16, 2016, in over 25 countries. The Series 1 was offered as an entry-level model priced at $249 for the 38 mm variant and $299 for the 42 mm, featuring an aluminum case in three colors (silver, space gray, gold) and the upgraded dual-core S1P processor derived from the original Apple Watch's single-core S1 for faster performance. In contrast, the Series 2, starting at $369 for aluminum models, introduced premium enhancements including cases, built-in GPS/ for independent location tracking without an , 50-meter water resistance suitable for shallow-water activities like swimming, and a display twice as bright at up to 1,000 nits compared to the Series 1's 500 nits. Both models shared core design elements, including 38 mm and 42 mm case sizes, displays with capabilities for pressure-sensitive interactions, a Digital Crown for , and compatibility with interchangeable bands via a connector. They featured the same health and fitness sensors: an optical heart rate sensor, , and for activity tracking, step counting, and basic workout monitoring, powered by watchOS 3, which added features like an expanded and improved integration. The Series 2 additionally included a barometric for precise data during hikes or runs. Connectivity relied on 4.0, (802.11b/g/n 2.4GHz), and NFC for , but Series 1 required an for GPS-dependent features like outdoor workouts, while Series 2's onboard GPS enabled standalone use. The S1P in Series 1 and the new S2 SiP in Series 2 both utilized dual-core processors, but the S2 offered a 50% faster performance and improved graphics rendering for smoother animations and app loading. Series 2's ceramic back enhanced durability and resistance, tested to ISO 22810:2010 standards for 50 meters, though Apple cautioned against high-velocity activities like . Battery life for both was rated at 18 hours of normal use, with fast charging not yet available. Series 1 maintained splash resistance similar to the original Apple Watch, adequate for rain or handwashing but not submersion.
FeatureSeries 1Series 2
ProcessorS1P (dual-core)S2 (dual-core, 50% faster)
Display BrightnessUp to 500 nitsUp to 1,000 nits (2x brighter)
GPSNo (relies on )Built-in GPS/
Water ResistanceSplash resistant50 meters
Case MaterialsAluminum onlyAluminum or
Back MaterialComposite
AltimeterNo
Starting Price (38 mm)$249$369
These models marked Apple's refinement of the platform, emphasizing health monitoring amid growing fitness trends, though independent reviews noted limitations in accuracy during intense exercise compared to chest straps. Series 1 and 2 were discontinued in September 2018 with the Series 4 launch, but remained supported via software updates until 4 in 2017 for Series 1.

Series 3

The Apple Watch Series 3 was announced on , , during Apple's event and released on September 22, 2017. It introduced built-in cellular connectivity for the first time in the lineup, enabling independent phone calls, messaging, and music streaming without an nearby, alongside GPS-only variants. Available in 38 mm and 42 mm case sizes, models included GPS-only versions in aluminum cases starting at $279 for 38 mm, and GPS + Cellular versions in aluminum ($379) or ($549), with storage at 8 GB for GPS models and 16 GB for cellular. Powered by the Apple S3 chip, a dual-core processor 70% faster than the S2, with an integrated W2 wireless chip for improved and performance, the Series 3 offered enhanced speed for apps and interactions. New hardware included a barometric for accurate elevation tracking and floor counting, faster GPS for precise location data, and an updated optical sensor for continuous monitoring. The device retained the Series 2's 50-meter water resistance, LTPO display (272 x 340 pixels at 38 mm, 312 x 390 at 42 mm), and up to 18 hours of battery life, with swim-proof capabilities certified to ISO standard 22810:2010. Software launched with watchOS 4, supporting features like fall detection precursors via improved motion sensors and enhanced fitness tracking for running, cycling, and swimming with automatic activity detection. The cellular models used technology with carrier plans, initially limited to select operators, expanding global availability by late 2017. Apple discontinued the Series 3 on September 7, 2022, after supporting updates through watchOS 8, citing hardware limitations for newer features like precise GPS positioning in watchOS 9.

Series 4

The Apple Watch Series 4 was announced on September 12, 2018, during Apple's "Gather Round" event and released for on September 14, with general availability beginning September 21, 2018. It marked the first significant redesign of the Apple Watch since its debut, featuring larger case sizes of 40 mm and 44 mm—up from 38 mm and 42 mm in prior models—and a thinner profile measuring 10.7 mm in depth for both variants. The display area increased by approximately 30% compared to the Series 3, utilizing LTPO displays with up to 1000 nits brightness, rounded corners, and thinner bezels to accommodate the expanded screen real estate. Powered by the new S4 system in package (SiP), which includes a 64-bit dual-core processor delivering up to twice the performance of the previous S3 chip while maintaining similar power efficiency, the Series 4 supported watchOS 5 out of the box. The device offered GPS-only and GPS + Cellular models, with the latter supporting LTE and UMTS connectivity via an eSIM; aluminum cases came in silver and space gray, while stainless steel options included gold, silver, and space black finishes. Audio improvements included a speaker 50% louder than predecessors, enabling clearer phone calls, Siri interactions, and a new Walkie-Talkie app for direct voice communication between compatible watches. Health monitoring advanced with the introduction of an electrocardiogram (ECG) app, utilizing a new electrical heart integrated into the Digital to generate single-lead ECG readings for detecting irregular heart rhythms like ; this feature received FDA clearance in the United States shortly after launch. Fall detection was added via upgraded and sensors capable of measuring impacts up to 32 g-forces and rotational acceleration up to 2000 rad/sec²; if a severe fall is detected and the user does not move for about a minute, the watch automatically calls services. The battery capacity saw a modest 4% increase to 1.113 watt-hours (approximately 292 mAh), supporting up to 18 hours of all-day use under normal conditions. Pricing started at $399 for the 40 GPS aluminum model and $499 for the 44 GPS version, with cellular and variants commanding higher prices up to $699. The Series 4 discontinued support for the original Apple Watch's 38 size and introduced a redesigned back with sapphire crystal over updated sensors, including optical monitoring. While the ECG and fall detection features enhanced proactive insights, their effectiveness relies on user activation and regulatory approvals varying by region.

Series 5 and First-Generation SE

The Apple Watch Series 5 was announced on September 10, 2019, during Apple's fall event and released for purchase on September 20, 2019. It introduced the always-on LTPO display, which dims to 5% brightness to show the time, complications, and select apps without requiring wrist elevation or touch input, powered by a low-temperature polysilicon display for efficiency. The device featured the S5 system in package (SiP) with a 64-bit dual-core processor, delivering up to 30% faster than the Series 4's S4 chip. Available in 40 mm and 44 mm case sizes, options included aluminum, , , and materials, with display resolutions of 324 x 394 pixels (40 mm) and 368 x 448 pixels (44 mm) at up to 1000 nits brightness. Key additions included a built-in for accurate heading information in Maps and workouts, international emergency calling via cellular models without needing local carrier setup, and a 32 GB storage capacity upgrade from 16 GB. Health functionalities encompassed the ECG app, cleared by the FDA for detecting through single-lead electrocardiograms, high/low notifications, and fall detection, which uses the and to identify hard falls and automatically call emergency services if the user does not respond within 60 seconds. The Series 5 maintained 50-meter water resistance, optical sensing, and GPS/GNSS tracking, with battery life rated at 18 hours under normal use. The first-generation Apple Watch SE, launched as an entry-level model, was announced on , 2020, and available starting , 2020. It shared the S5 SiP processor and ion-X strengthened glass display with the Series 5 but excluded the always-on capability and dedicated ECG electrical heart , relying instead on software-based heart rhythm analysis via the optical . Offered only in aluminum cases for 40 mm (dimensions: 40 x 34 x 10.7 mm, weight ~30.7 g GPS model) and 44 mm (44 x 38 x 10.7 mm, ~36.4 g) sizes, in space gray or silver finishes, it prioritized cost reduction while retaining Retina LTPO displays without . The SE supported fall detection, high-precision dual-frequency GPS, 50-meter water resistance, and core fitness metrics like heart rate zones, swim tracking, and sleep stage analysis via later watchOS updates. Cellular variants enabled independent calls, texts, and streaming, with the same 18-hour battery life and 32 GB storage as the Series 5. Positioned at $279 starting price versus the Series 5's original $399, the SE targeted users seeking essential features without premium sensors, effectively utilizing Series 5 hardware lineage for broader accessibility. Both models ran 6 at launch, with the Series 5 discontinued upon SE introduction to streamline the lineup.

Series 6

The Apple Watch Series 6 was announced on September 15, 2020, alongside the Apple Watch SE and updates to watchOS 7. It became available for pre-order on the same day and began shipping on September 18, 2020. Apple discontinued the model on September 14, 2021, following the release of the Series 7. The Series 6 introduced hardware enhancements focused on health monitoring and performance, including a new blood oxygen sensor and the S6 processor. Available in 40 mm and 44 mm case sizes, the Series 6 retained the squared design with rounded corners introduced in the Series 4. Case options included aluminum in Silver, Space Gray, Gold, Blue, and finishes; in Silver, Graphite, and Gold; and cases. The display used an Always-On LTPO panel, with the 44 mm model featuring a 1.78-inch screen. Pricing started at $399 for the GPS model and $499 for GPS + Cellular variants. The S6 system in package, fabricated on a , delivered up to 20% faster CPU performance than the S5 chip in the Series 5. It powered features like an always-on for real-time tracking. The device included 32 GB of storage and ran 7 or later, supporting Family Setup for independent use without an . A key addition was the blood oxygen sensor, which uses and LEDs along with photodiodes to measure blood (SpO2) levels noninvasively. Apple positioned this for wellness insights, such as monitoring during workouts or sleep, though the company noted it was not intended for . Other sensors included the electrical heart rate sensor for ECG readings, optical heart rate monitoring, , , and GPS. The watch achieved 50-meter water resistance and offered up to 18 hours of battery life.

Series 7

The Apple Watch Series 7 was announced on September 14, 2021, and released on October 15, 2021. It succeeded the Series 6 model and introduced a reengineered Always-On LTPO display with approximately 20% more screen area and 40% thinner borders compared to the Series 6, available in 41 mm and 45 mm case sizes. The display reached up to 1,000 nits of , enabling better visibility in direct sunlight, and supported a full-width on-screen keyboard for typing, a feature absent in prior models. Hardware enhancements included the S7 SiP, featuring a 64-bit dual-core processor derived from the same CPU architecture as the S6 chip in the Series 6, paired with 1 GB RAM and 32 GB storage. The device retained sensors from the previous generation, such as blood oxygen, electrical heart rate, accelerometer, gyroscope, and altimeter, while adding IP6X dust resistance and a more crack-resistant front crystal made from Ion-X strengthened glass or optional sapphire crystal on higher-end models. Charging improved significantly, achieving 80% capacity in 45 minutes via USB-C magnetic puck, compared to over an hour for the Series 6, though overall battery life remained at 18 hours of normal use. The Series 7 launched with watchOS 8, which expanded fitness tracking with features like customizable watch faces, improved workout metrics, and the Messages app's inline replies, though core health monitoring capabilities like ECG and irregular rhythm notifications carried over unchanged from the Series 6. Case materials included aluminum in colors such as midnight, starlight, green, and blue, with and titanium options for premium variants starting at $399 for the base GPS aluminum model. Reception highlighted the display and charging upgrades as practical advancements, with reviewers noting the larger screen facilitated easier interaction and text visibility, positioning it as the leading despite minimal changes to processing power or sensors. Critics described it as an incremental evolution rather than revolutionary, with the Series 6 remaining a viable alternative at lower prices post-launch. User feedback emphasized satisfaction with and , reflected in high retail ratings averaging 4.8 out of 5 from thousands of reviews. In the second-hand market in Spain for the 45 mm GPS model, as of 2024, prices on Wallapop and Milanuncios range from 150€ to 280€, depending on the condition, battery health, accessories, and original box inclusion. Models in good condition typically range from 180€ to 240€. For 2025 or 2026, following the release of newer models such as Series 10 and beyond, prices are projected to decrease to 100€ to 220€, varying by demand and condition. Exact future prices are unavailable; current listings on the platforms should be consulted directly.

Series 8, Second-Generation SE, and Ultra

Apple announced the Apple Watch Series 8, second-generation SE, and Ultra on , 2022, during its "Far Out" event. The Series 8 and second-generation SE became available on September 16, 2022, while the Ultra launched on September 23, 2022. All three models incorporate the S8 system in package (SiP), featuring a 64-bit dual-core processor identical to the S6 and S7 chips but with enhanced high-g and for improved motion detection. They run 9 at launch, supporting features like , which uses a new 256 to identify severe car crashes and initiate emergency calls. The Series 8 introduces wrist temperature sensing, enabling retrospective estimates via variations tracked overnight, building on cycle logging capabilities. It retains prior sensors including electrical for ECG, blood oxygen measurement, and optical monitoring, alongside fall detection. Available in 41 mm and 45 mm aluminum cases, it features an always-on LTPO display reaching 1,000 nits brightness, with 18-hour battery life and fast charging to 80% in 45 minutes. GPS and GPS + Cellular variants start at $399 and $499, respectively. The second-generation SE shares the S8 chip and crash detection but omits advanced sensors like temperature, ECG, and blood oxygen, as well as always-on display and fast charging. Offered in 40 mm and 44 mm aluminum cases with Retina LTPO OLED displays up to 1,000 nits (non always-on), it provides core fitness tracking, heart rate monitoring, and sleep stages analysis. Battery life matches the Series 8 at 18 hours with standard charging. Priced from $249 for GPS and $299 for GPS + Cellular, it targets budget-conscious users seeking essential smartwatch functions. The Ultra targets endurance athletes and adventurers with a 49 mm aerospace-grade case, offering corrosion resistance and a flat crystal over the largest, brightest display at up to 2,000 nits. It includes all Series 8 sensors plus a to 40 meters, water temperature sensor, dual-frequency GPS for precision in remote areas—supporting advanced metrics for endurance running including running power, running form, vertical oscillation, stride length, and ground contact time—and an 86-decibel siren for emergencies. It enables seamless integration with iPhone and AirPods for music playback, calls, and texts; custom workouts, race route planning with Pace Pro, and offline maps; as well as standalone capability for GPS tracking and music during phone-free runs. A customizable Action button enables quick access to functions like workouts or the Backtrack feature for retracing paths. Battery lasts 36 hours normally or up to 60 hours in low-power mode, supporting extended endurance activities including sleep tracking, with standard charging. It starts at $799 for GPS + Cellular only.
FeatureSeries 8SE (2nd gen)Ultra
Case sizes41 mm, 45 mm aluminum40 mm, 44 mm aluminum49 mm titanium
DisplayAlways-on LTPO OLED, 1,000 nitsLTPO OLED, 1,000 nits (no always-on)LTPO OLED, 2,000 nits
Key sensorsTemp, ECG, BOx, crash detectionCrash detection, heart rateAll Series 8 + depth, water temp
Battery life18 hours, fast charge18 hours, standard charge36 hours (60 low power), standard
Starting price (GPS)$399$249N/A (Cellular only $799)

Series 9 and Ultra 2

The Apple Watch Series 9 and Ultra 2 were announced on September 12, 2023, during Apple's annual fall event, with pre-orders starting the same day and general availability beginning September 22, 2023. Both models introduced the S9 system in package (SiP), a 64-bit dual-core processor enabling on-device processing for faster response times without cloud dependency, and a new double-tap gesture allowing users to perform actions like answering calls or scrolling by tapping the and together. They also featured always-on LTPO displays with up to 2,000 nits peak brightness for Series 9 (3,000 nits for Ultra 2), supporting chip for Precision Finding of paired iPhones, and health sensors including ECG, irregular heart rhythm notifications, and skin temperature measurement. The Series 9 targeted everyday users with 41 mm and 45 mm aluminum cases in colors like midnight, starlight, silver, and (PRODUCT)RED, weighing 31.9–42.3 grams depending on size and GPS/cellular variant, and offering up to 18 hours of battery life. It launched at $399 for the base GPS model, emphasizing compact design with ion-X strengthened glass and water resistance to 50 meters. The Ultra 2, positioned for rugged and outdoor activities, retained the 49 mm titanium case from its predecessor but added a black titanium option in September 2024, weighing 61.4–61.8 grams with 100-meter water resistance, a customizable Action button, dual-frequency GPS for superior accuracy in challenging environments, an 86-decibel emergency siren, and up to 36 hours of battery life (72 hours in Low Power Mode). Priced at $799, it included dive computer functionality via the Oceanic+ app for recreational scuba up to 40 meters. Both models shipped with 10, supporting features like Smart Stack widgets and improved cycling workout tracking, with 64 GB storage. However, blood oxygen monitoring—enabled by a redesigned LED —was disabled via software on U.S.-sold units of Series 9 and Ultra 2 starting January 18, 2024, following a U.S. Commission ruling that the feature infringed patents held by medical device firm , whom Apple had accused of design poaching in a countersuit. Apple redesigned the arrangement to circumvent the import ban, restoring the feature through a update in August 2025 for compatible models, though challenged U.S. Customs and Border Protection's approval, alleging improper circumvention. Outside the U.S., the feature remained available uninterrupted. Key differences include the Ultra 2's superior durability (MIL-STD 810H certified), brighter display for outdoor visibility, and extended battery for multi-day use, versus the Series 9's lighter, more affordable form factor suited to urban lifestyles; both share core metrics but the Ultra excels in precision GPS and depth gauging for activities like or diving. Later updates added sleep apnea notifications via analysis of breathing disturbances, requiring Series 9, Ultra 2, or newer.

Series 10

The Apple Watch Series 10 was announced by Apple on , 2024, during the "It's Glowtime" event and became available for purchase starting , 2024. It is powered by the S10 system in package (SiP), which enables features like double-tap gesture support and on-device processing. Pricing begins at $399 for the 42 mm GPS model, with cellular variants adding $100 and titanium cases increasing the cost further. The device introduces the largest display yet, with wide-angle panels offering up to 40% brighter viewing at angles and a maximum brightness of 2,000 nits. Case sizes are 42 and 46 , with a uniform thickness of 9.7 , making it the thinnest Apple Watch to date. Aluminum cases are available in , Rose , and Silver finishes, while titanium options include Natural, , and Slate. Weights for aluminum GPS models are approximately 34.4 g (42 ) and 41.7 g (46 ). It features 64 GB of storage and runs 11 out of the box, with support up to 26. Battery life is rated for up to 18 hours of normal use or 36 hours in low power mode, with the fastest charging in the lineup—reaching 80% in 30 minutes. New hardware includes a depth gauge measuring up to 6 meters and a water temperature sensor, enabling snorkeling and shallow-water activity tracking via the Depth app. Health monitoring encompasses sleep apnea detection notifications, alongside existing sensors for heart rate, ECG, and temperature. In U.S. models, the blood oxygen feature is disabled due to an ongoing patent dispute and import restrictions imposed by the International Trade Commission.
ModelCase SizeMaterialsKey Display Specs
GPS42 mmAluminum1.65-inch LTPO3 , 416 x 496 pixels
GPS + Cellular46 mm1.81-inch LTPO3 , larger area up to 1220 sq mm

Series 11, Third-Generation SE, and Ultra 3

Apple announced the Apple Watch Series 11, third-generation SE (SE 3), and Ultra 3 on , 2025, during its annual fall event, with preorders starting immediately and general availability beginning September 19, 2025. The Series 11 serves as the flagship model, introducing advanced health monitoring features such as notifications and a sleep score metric derived from integrated data on , , and stages. It also incorporates Workout Buddy, an Apple Intelligence-powered coaching tool that provides real-time form feedback and adaptive workout adjustments via on-device processing. Powered by the new S11 chip, the Series 11 offers up to 24 hours of battery life, a thinner than the Series 10, enhanced scratch-resistant display glass, and 50 meters water resistance suitable for general swimming in shallow water, while maintaining compatibility with existing 41mm and 45mm case sizes. The third-generation Apple Watch SE emphasizes affordability and core functionality, retaining the aluminum case design from prior SE models but adding up to twice the charging speed of the second-generation SE, enabling a full charge in approximately 45 minutes. Available in 40mm and 44mm sizes, it includes essential sensors for heart rate monitoring, activity tracking, and fall/crash detection, alongside watchOS 11 features like improved fitness algorithms, but omits advanced capabilities such as blood oxygen sensing or ECG found in higher-tier models. Priced starting at $249, the SE 3 targets entry-level users seeking basic health and connectivity without premium materials or extended battery life. The Apple Watch Ultra 3 targets extreme sports and outdoor enthusiasts with a rugged 49mm aerospace-grade case weighing 61.6 grams in natural finish, featuring dual-frequency GPS, cellular connectivity, and built-in communications for emergency messaging in areas without cellular or coverage. Its Always-On reaches up to 3,000 nits of brightness with a larger 1.98-inch area and flat crystal front, supporting up to 42 hours of battery life under normal use and 100 meters water resistance with dive certification suitable for recreational scuba diving and extreme underwater activities, including precision depth gauging up to 40 meters. The Ultra 3 integrates the S11 chip for enhanced performance in low-power modes and adds siren functionality audible up to 180 meters, building on the Ultra 2's MIL-STD-810H durability standards. Starting at $799, it differentiates from the Series 11 through its larger form factor, extended runtime, and specialized sensors like the Oceanic+ app integration for water sports. All three models require an or later running 18 or newer for setup and full functionality.

Hardware

Design and Materials

The Apple Watch utilizes a unibody rectangular case with rounded corners, incorporating a rotating Digital Crown for navigation and a side button for power and app launching. Case materials differ across models to balance weight, durability, and cost: entry-level variants feature anodized 7000-series aluminum, which is lightweight at approximately 32 grams for 41mm sizes and offers good corrosion resistance through its oxide layer. Premium stainless steel cases, made from 316L alloy, provide enhanced scratch resistance and a premium finish but weigh more, around 42 grams for similar sizes, due to higher density. Titanium cases, aerospace-grade and used in high-end Series models and the Ultra line, achieve a strength-to-weight ratio superior to stainless steel, weighing about 34-45 grams while resisting corrosion better in harsh environments. Ceramic cases, exclusive to early Edition models, delivered exceptional hardness but were prone to chipping and later discontinued. Display covers vary by case material: aluminum models employ Ion-X strengthened , chemically treated for impact resistance up to four times that of prior generations in recent iterations, though it scratches more readily than alternatives. crystal, standard on , , and Ultra models, ranks higher on the Mohs hardness scale for superior scratch resistance—resisting keys and coins—but is more brittle and susceptible to shattering from drops compared to Ion-X. Recent aluminum Series 11 models feature Ion-X with twice the scratch resistance of Series 10 equivalents. The rear housing typically includes a or metal back with apertures for sensors, facilitating better skin contact and signal transmission for health monitoring; backs, used in most models until Series 10, enhance , while Series 10 and later aluminum variants shifted to recycled metal and for efficiency. All Apple Watches from Series 2 onward maintain a 50-meter water resistance rating under ISO standard 22810:2010, permitting shallow-water activities like but not high-speed water sports or diving without additional certification. The Ultra series extends this to 100 meters with a up to 40 meters, IP6X dust resistance, and MIL-STD 810H compliance for rugged use. Recent models incorporate sustainable materials, such as 100% recycled aluminum or cases.

Display and Sizing Options

The Apple Watch case sizes have evolved across generations to offer options for different wrist sizes, with small and large variants generally compatible for band interchangeability within their respective groups (38/40/41 mm and 42/44/45/49 mm). Original models from the first generation through Series 3 provided 38 mm (small) and 42 mm (large) cases. Series 4 through Series 6 and the first-generation SE shifted to slightly larger 40 mm and 44 mm options, increasing display area by approximately 30% compared to predecessors while maintaining similar proportions. Starting with Series 7, SE (second generation), and continuing through Series 10, cases measure 41 mm (small) and 45 mm (large), further expanding usable screen real estate. The series, introduced in 2022, exclusively uses a 49 mm case for enhanced durability and visibility in rugged environments.
GenerationSmall Case SizeLarge Case Size
Series 0–338 mm42 mm
Series 4–6, SE (1st gen)40 mm44 mm
Series 7–10, SE (2nd gen)41 mm45 mm
Ultra (1st–2nd gen)49 mm
All Apple Watch models employ LTPO displays, which support variable refresh rates for power efficiency; resolutions scale with case size (e.g., 394 × 324 pixels for 41 mm models, 448 × 368 for 45 mm). Ion-X strengthened glass covers standard models, while crystal is used on higher-end variants like or Ultra editions for superior scratch resistance. Always-on functionality, enabled by LTPO technology's ability to drop to 1 Hz refresh, was introduced in Series 5, dimming the display when the wrist is down to show key complications without full activation. Series 7 onward added ProMotion for adaptive refresh rates up to 60 Hz, reducing motion blur during scrolling and workouts. The Series 10 introduced a wide-angle variant, optimizing off-axis viewing and achieving peak brightness of up to 2,000 nits for better outdoor legibility, compared to 1,000 nits in prior standard models. Ultra models match or exceed this brightness level in their larger 49 mm displays.

Sensors and Input Methods

The Apple Watch employs an array of sensors embedded primarily in the rear ceramic or crystal to capture biometric, motion, and environmental data. Core sensors across models include a multi-LED optical sensor for photoplethysmography-based pulse monitoring, introduced in the original 2015 release, and an capable of detecting up to 32 g-forces for and fall detection, added in Series 4 in 2018. A gyroscope complements the accelerometer for orientation and gesture detection, while an always-on tracks elevation changes and a built-in provides directional data, both present since early generations. Wrist detection, enabled by default using the optical heart rate sensor and accelerometer, determines if the Apple Watch is worn on the wrist. Disabling it prevents automatic locking upon removal, limits or disables background health measurements such as heart rate and blood oxygen, eliminates stand credits and reminders, impairs safety features like automatic emergency calls after falls, requires passcode entry for Apple Pay instead of wrist-based authentication, may cause notification duplication or fallback to the paired iPhone, and reduces functionality for other wrist-presence-dependent features. It is recommended for security via automatic locking, data accuracy, and enabling features including wrist-based Apple Pay authentication, auto-unlock with a paired iPhone, health monitoring, activity tracking, stand reminders, and safety functions such as Fall Detection emergency calls. Apple recommends wearing the device on the top (dorsal) side of the wrist to optimize sensor performance, as the sensors require consistent skin contact in that position. While users can rotate the watch to wear it on the inside (ventral) side for preference, screen protection, or easier glancing, this may compromise accuracy for features like heart rate, blood oxygen, and ECG due to differences in skin contact and blood flow; user reports indicate mixed results, with some maintaining comparable accuracy and others experiencing reductions during activity. No dedicated setting exists for inside-wrist orientation; adjustments are limited to left or right wrist and Digital Crown position. Troubleshooting for detection issues involves ensuring a snug fit, cleaning sensors, and avoiding tattoos or coverings that interfere with readings. Advanced health-oriented sensors expanded in later series: the electrical heart sensor for electrocardiogram (ECG) readings debuted in Series 4, enabling single-lead ECG classification for detection; blood oxygen measurement via red and LEDs arrived in Series 6 in 2020; and wrist temperature sensing, using two sensors to track relative changes from a baseline wrist temperature established after approximately five nights of sleep tracking (not providing absolute body temperature values in degrees like a traditional thermometer for fever checking and not intended as a medical device for diagnosis or treatment), was introduced in Series 8 in 2022. GPS for location tracking without an became standard in Series 2 in 2016, with dual-frequency GPS in Series 7 and later for improved accuracy. GPS + Cellular models incorporate an eSIM for independent cellular connectivity, but activation requires the paired iPhone to have an active cellular plan with a compatible carrier, typically the same carrier; without it, the watch pairs and functions via the iPhone connection or Wi-Fi, but independent cellular features do not work. However, GPS + Cellular models can share their location via Find My independently using their built-in GPS and cellular connection, even when the paired iPhone is left at home, provided cellular service is active and the Watch is signed in to iCloud. Ambient light sensors adjust display brightness automatically across all models. Input methods prioritize tactile and gesture-based interaction to suit the device's form factor. The Digital Crown, a rotating and clickable mechanical dial on the side, serves as the primary navigation tool for scrolling lists, zooming interfaces, and returning to the home screen, offering precise control over the . The side button handles power functions, app shortcuts, and payments via NFC, while the supports gestures such as swiping, tapping, and pinching for menu navigation and content manipulation. Additional inputs include wrist-detection gestures like flicking for wake-up, double-tap (pinch-to-action) introduced in Series 9 in 2023 for hands-free control, and an Action button on Ultra models for customizable shortcuts. Voice input via microphone activates for dictation and commands.

Battery and Charging

The Apple Watch incorporates a built-in rechargeable , which provides up to 18 hours of battery life under normal mixed usage conditions across most standard models, including the Series 9, Series 10, and SE generations; this benchmark assumes 90 time checks, 90 notifications, 45 minutes of app use, and a 60-minute workout with music playback via from the wrist. Apple Watch Ultra models extend this to up to 36 hours for the Ultra 2 and 42 hours for the Ultra 3 in normal use, benefiting from larger battery capacities suited to their rugged, oversized for extended outdoor activities. Low Power Mode, accessible via settings, further prolongs runtime by disabling features like the and background app refresh, yielding up to 36 hours on standard models and 72 hours on Ultra variants. Power Reserve mode is a more extreme power-saving feature that can be activated manually through settings or automatically prompted at critically low battery levels. In Power Reserve mode, the Apple Watch disables most features and displays only the time in red numerals, significantly extending battery life. Apple states this mode allows the watch to show the time for several days. User reports and sources indicate it can last up to 72 hours or longer, depending on the model, battery condition, and usage before entering the mode. Battery performance degrades over time due to inherent lithium-ion chemistry limitations, with Apple recommending monitoring via the Watch app on paired iPhones, where users can view capacity as a of original design and usage history; capacities typically retain above 80% after 1,000 charge cycles under ideal conditions. Real-world endurance varies based on factors such as screen brightness, GPS usage during workouts, and cellular connectivity enabled via eSIM; for cellular-capable models, typical battery life ranges from 1 to 1.5 days under normal mixed usage including periodic independent cellular activity, extending to up to 2 days with lighter use and minimal cellular reliance, though it often falls short of official claims in intensive scenarios like continuous monitoring or third-party app execution, while empirical tests confirm the 18-hour rating holds for moderate daily routines primarily tethered via Bluetooth. Charging employs inductive through a puck-shaped accessory that aligns with the device's rear , connecting via USB-A or cables to a ; standard charging from 0% to full requires approximately 2.5 hours. From Series 7 onward, fast charging capability—requiring a dedicated Magnetic Fast Charging Cable and an 18W or higher Power Delivery —achieves up to 80% charge in 45 minutes, prioritizing rapid top-ups for users with overnight charging habits. Optimized Battery Charging is an on-device machine learning feature that learns the user's daily charging routine, such as overnight charging, and delays charging past 80% until shortly before the typical time of removal from the charger; it holds the battery at 75-80% during extended sessions to reduce chemical aging of lithium-ion batteries and extend lifespan. The feature is always enabled and cannot be permanently turned off on Apple Watch Ultra models, including the Ultra 2, and Series 9 or later; it includes Optimized Charge Limit, available in watchOS 10 and later, which adjusts the charging threshold based on usage patterns.

Bands and Accessories

The Apple Watch features a quick-release band mechanism introduced with the original model in April 2015, enabling tool-free attachment and detachment via a simple slide-and-lock system on the lugs. This design accommodates a wide array of official bands tailored for different activities, aesthetics, and wrist sizes, with compatibility determined by case dimensions: 38mm, 40mm, or 41mm bands fit smaller wrists on Series 1 through Series 10 models (excluding Ultra), while 42mm, 44mm, or 45mm bands suit larger cases, and 49mm bands are specific to Ultra models. Apple offers bands in four primary material categories as of 2025: fluoroelastomer rubber for durable, water-resistant options like the Sport Band and Nike Sport Band; textiles such as nylon weaves in the Sport Loop, Trail Loop, and Alpine Loop for breathability during exercise; 316L stainless steel mesh or links in the Milanese Loop and Link Bracelet—a stainless steel band offering a classic watch-like high-end feel with substantial weight but high durability for long-term use—for premium, adjustable fits; and Grade 5 titanium variants for lighter weight and corrosion resistance, often paired with Ultra models. Specialized bands include the Ocean Band, a tubular fluoroelastomer design with adjustable extensions for water sports, and the Braided Solo Loop, a stretchable yarn weave without clasps for seamless wear. Leather bands, once available, were discontinued by Apple in September 2023 to prioritize environmental sustainability, shifting focus to recycled and synthetic alternatives. Third-party bands adhering to Apple's sizing and attachment standards remain compatible across models, though official bands emphasize precision engineering for fit and durability, such as magnetic closures in the Modern Buckle. Beyond bands, official Apple accessories center on charging solutions, including the included magnetic puck charger (evolving from USB-A to compatibility with Series 7 and later) and standalone fast chargers supporting up to 80% charge in 45 minutes for Series 7–10 models. Apple also sells multi-device wireless charging stands compatible with Apple Watch, such as Qi-certified docks, though third-party options like and dominate for integrated stands that hold the watch upright during overnight charging. Protective cases and screen covers are not offered by Apple, reflecting the device's IP6X dust and 50-meter water resistance ratings, but aftermarket variants exist for added scratch protection without voiding if properly fitted. Band storage racks and travel adapters round out accessory ecosystems, often from partners emphasizing alignment for efficient .

Software

watchOS Version History

watchOS 1.0 launched on April 24, 2015, with the original Apple Watch, establishing core features including notifications, timekeeping, glances for quick data access, and basic activity tracking via the Activity app. Subsequent versions incremented annually, enhancing independence from , expanding native app support, and integrating advanced health sensors as hardware evolved; for instance, watchOS 2 (September 21, 2015) enabled third-party app development on the device itself, while watchOS 3 (September 13, 2016) improved app launch speeds by up to 30% through background app refresh. watchOS 10, released September 18, 2023, redesigned apps with a bolder interface for better readability, introduced the Smart Stack for contextual widgets, added cycling workout metrics like power output, and incorporated minutes for tracking. watchOS 11, available from September 16, 2024, added the Vitals app aggregating overnight metrics such as and , tracking in the Cycle app, and detection using data for breathing disturbances. In a shift to year-based naming for consistency across Apple's ecosystems—mirroring changes in and others—watchOS 26 superseded the expected watchOS 12, releasing September 15, 2025, with hypertension trend notifications using optical heart sensor data to detect patterns suggestive of elevated blood pressure, a native sleep score , a "Liquid Glass" UI redesign for fluidity, and Workout Buddy for real-time audio coaching.
VersionRelease DateKey Additions
watchOS 10September 18, 2023Smart Stack widgets, redesigned apps, power zones
watchOS 11September 16, 2024Vitals app, notifications, training load analytics
watchOS 26September 15, 2025 alerts, score, wrist-flick dismissals

Core Operating Features

, Apple's proprietary operating system for the Apple Watch, powers a touch-based interface optimized for wrist-worn use, integrating a capacitive with the physical Digital Crown for precise navigation. The Digital Crown, located on the side of the device, enables scrolling through lists, zooming in apps like Maps, and returning to the with a single press; it also supports haptic feedback for tactile confirmation of actions. Touch gestures include taps for selection, swipes for navigation between screens or notifications, and double-tap or pinch motions for quick controls like starting workouts or dismissing alerts, with (replaced by haptic touch in later models) allowing access to contextual menus. The home screen displays a grid or honeycomb arrangement of app icons, customizable via the paired , with watch faces serving as the primary timekeeping interface; these faces incorporate complications—glanceable widgets showing data such as , battery level, or calendar events from integrated apps. The Speak Time feature provides an alternative method to announce the time audibly upon double-tapping the display, with customization options including "Always Speak" for audible output regardless of Silent Mode or "Control With Silent Mode," which switches to haptic vibrations via Taptic Time when the watch is silenced. Notifications from the connected mirror to the watch via or , appearing as haptic-vibration alerts with visual banners; users can reply using predefined responses, dictation, or scribble input, and dismiss via wrist flick or swipe in recent versions like 11. The Smart Stack feature aggregates context-aware widgets and notification summaries, scrollable via the Digital Crown, to prioritize relevant information like upcoming appointments or changes. Core communication functions include handling incoming calls that notify on both the paired iPhone (when nearby) and the Apple Watch, allowing users to answer via the Watch's touchscreen to use its speaker and microphone or connected Bluetooth devices like AirPods; standalone cellular or Wi-Fi-enabled calls and messages are supported on compatible models, with the Phone app providing speakerphone mode and the Messages app allowing threaded conversations synced from iPhone. Siri provides voice-activated assistance for tasks like setting timers, sending texts, or querying information, processing queries on-device for privacy in supported models. Apple Pay integration enables contactless payments via double-click of the side button and wrist authentication, while Control Center—accessed by pressing the side button—offers toggles for settings like Do Not Disturb, flashlight, and connectivity options. All features require pairing with an iPhone running a compatible iOS version, ensuring seamless data syncing but limiting standalone operation for non-cellular variants.

Third-Party App Ecosystem

Third-party applications for the Apple Watch became available upon the device's launch on April 24, 2015, with over 3,000 titles offered through the App Store at introduction. These early apps primarily functioned as extensions of iPhone counterparts, relying on the paired iOS device for processing due to the original Apple Watch's limited hardware capabilities. Native standalone app support arrived with watchOS 2 later in 2015, enabling independent execution on the watch itself via the watchOS SDK integrated into Xcode. Development for watchOS utilizes Swift and SwiftUI frameworks, allowing third-party creators to access APIs for sensors, notifications, and complications—small widgets on the watch face. Apple does not permit fully independent third-party watch faces, prioritizing design uniformity, performance consistency, and long-term compatibility with updates. Developers work around this by providing complications for official watch faces, contributing to photo backgrounds, sharing configurations with their data, or running custom displays within apps, though these approaches can vary in battery impact and always-on display support. However, the ecosystem remains constrained by the device's form factor, with apps optimized for quick glances rather than prolonged interaction; common categories include fitness tracking (e.g., for running metrics and Golfshot for golf course navigation), music streaming (e.g., ), and productivity tools (e.g., Outlook for email previews). Apple's own reports highlight at least 20 third-party health and fitness apps surpassing 1 million downloads each by 2016, underscoring early adoption in specialized domains. Despite these advancements, third-party development faces persistent hurdles, including frequent debugging instability during testing—such as unreliable connections between simulators and physical devices—and battery drain from background processes. Developer reluctance persists due to Apple's dominance in core features via first-party apps, reducing incentive for standalone titles; many third-party offerings thus serve as lightweight companions rather than full experiences. Recent updates, like expanded APIs in 10 (released September 2023), have improved integration for contextual features such as Smart Stack widgets, yet the overall app corpus lags behind , with estimates suggesting thousands rather than millions of dedicated watch apps amid the broader App Store's 1.9 million total titles as of 2024. This disparity reflects causal limits of wrist-worn hardware, prioritizing utility over expansive software ecosystems.

Health and Fitness Features

Sensor-Based Capabilities

The Apple Watch employs an array of sensors to facilitate real-time health and fitness monitoring, including optical and electrical heart sensors, blood , temperature sensor, , , , and GPS. In models from Series 10 onward, additional and water temperature sensors enhance aquatic activity tracking. These sensors collectively enable features such as continuous measurement, electrocardiogram (ECG) recordings, blood oxygen saturation (SpO2) assessments, wrist temperature deviations for physiological insights, fall and , and elevation changes. Optical heart rate sensing, utilizing photoplethysmography via green and LEDs, provides continuous monitoring with demonstrated accuracy in low-intensity scenarios, such as walking at 4 km/h, where mean bias against reference devices is trivial. Studies in cardiovascular patients confirm clinically acceptable precision for 30-second averages during , though performance degrades at high intensities across wearables, including the Apple Watch. However, Apple Support notes that heart rate readings can be inaccurate, show unexpectedly high values, or cut out due to improper fit (too loose), excessive arm movement during activities, tattoos on the wrist, cold temperatures, poor blood flow, or a dirty sensor. Apple recommends wearing the watch snugly (but comfortably) on the top of the wrist, keeping the sensor clean, avoiding intense arm-swinging activities, and ensuring good skin contact to improve accuracy. If issues persist, users should restart the Apple Watch, update watchOS, or contact Apple Support for potential hardware issues. The electrical heart sensor enables single-lead ECG recordings for detecting (AFib), receiving FDA de novo clearance in 2018 for users over 22 years without prior AFib diagnosis. Irregular rhythm notifications, powered by the optical sensor's periodic checks, alert users to potential AFib episodes, with the AFib History feature qualified by the FDA in 2024 for use in estimating AFib burden. In mainland China, the Atrial Fibrillation History feature became available as of February 2026 for compatible Apple Watches following approval by the National Medical Products Administration on December 26, 2025, and rollout via watchOS updates. Prerequisites include a confirmed AFib diagnosis, age 22 or older, and sufficient watch wear time, such as 5 or more days with at least 12 hours per day for weekly estimates. To enable the feature, update the Apple Watch to the latest watchOS version, then on the paired iPhone, open the Health app, navigate to Browse > Heart, scroll to "Learn more about Health features," tap "Set up" under Atrial Fibrillation History (房颤历史), and follow the on-screen instructions. The Apple Watch does not have an official feature for detecting cardiomyopathy or structural heart diseases like heart muscle weakening. Official heart health features include the ECG app (FDA-cleared for classifying atrial fibrillation in users 22+), irregular heart rhythm notifications (for potential AFib), high and low heart rate notifications, and cardio fitness estimates; these do not detect cardiomyopathy. Research studies have explored using Apple Watch data to identify signs of reduced ejection fraction or heart failure (related to some cardiomyopathies), but these are not official Apple capabilities or FDA-approved features. Hypertension notifications utilize data from the optical heart sensor to analyze blood vessel responses over 30-day periods, detecting patterns suggestive of chronic high blood pressure trends and notifying users to consult a healthcare provider and log blood pressure with a traditional cuff; the feature is available on Series 9 and later models, as well as Ultra 2 and later, with compatible watchOS versions, but is not diagnostic and excludes users under 22, pregnant individuals, or those previously diagnosed with hypertension. Blood oxygen sensing, introduced in Series 6, measures SpO2 levels using red and light absorption, supporting features like notifications in 11. To obtain a reliable blood oxygen reading on Apple Watch, wear the watch snugly on the wrist for proper sensor contact, remain still during the measurement, keep your arm steady, and avoid using Low Power Mode or Power Reserve, as these may disable or affect the feature. Empirical validation indicates 95% limits of agreement of -5.8% to +5.9% against clinical oximeters when SpO2 exceeds 90%, with potential inaccuracies from motion, tattoos, or darker skin tones due to light scattering. Sleep tracking utilizes accelerometer, heart rate, and respiratory data to estimate sleep duration, stages, and quality; Apple Watch measures respiratory rate (breaths per minute) during sleep using motion sensors such as the accelerometer to detect breathing patterns. It does not define a universal "normal" range but establishes a personalized typical range based on the user's historical data in the Vitals app, notifying the user if values fall outside this range. For context, the medically accepted normal respiratory rate for healthy adults at rest or during sleep is 12-20 breaths per minute. The Sleep Score rates sleep from 0-100 based on duration (up to 50 points), consistency over recent nights (up to 30 points), and quality including interruptions (up to 20 points), categorized from Very Low to Very High (above 85 excellent). sensing, available since Series 8, tracks subtle wrist shifts overnight, informing cycle tracking, retrospective estimates, and basal metabolic insights, though it requires consistent wear for baseline establishment. Motion-based capabilities rely on high-g accelerometers and high dynamic range gyroscopes to detect falls since Series 4, triggering emergency calls if users remain unresponsive, and vehicle crash detection from Series 8 via algorithm analysis of wrist and impact data. The always-on altimeter monitors elevation for hiking and stair climbing metrics, while GPS enables precise outdoor pace and distance tracking. For water activities, Series 10's depth gauge measures up to 6 meters and water temperature sensor logs environmental data, aiding snorkeling and scuba profiling without dedicated dive computers. For optimal sensor accuracy and to minimize skin irritation or discomfort, Apple recommends wearing the device comfortably on the top of the wrist above the wrist bone, with a snug but not overly tight fit that allows skin to breathe, tightening during exercise and loosening afterward, regular cleaning of the watch and skin, and periodic removal for rest. These sensor integrations prioritize user convenience but are not substitutes for professional medical evaluation, with capabilities varying by model and regulatory approvals.

Empirical Validation and Studies

The Apple Heart Study, a prospective digital trial involving 419,297 participants conducted between 2017 and 2019, evaluated the Apple Watch's optical heart sensor for detecting irregular pulse rhythms indicative of (AF). The study found that the irregular pulse notification feature had a positive predictive value of 84% for AF episodes lasting at least 5 minutes when compared to patch ECG monitoring, with sensitivity of 98.3% and specificity of 99.6% in subsequent ECG-confirmed cases. Independent validation in a 2025 of 12 studies reported pooled sensitivity of 94% and specificity of 98% for Apple Watch ECG in detecting AF against 12-lead ECG gold standards. Heart rate monitoring via photoplethysmography (PPG) on the Apple Watch demonstrates high accuracy during rest and low-to-moderate intensity activities, with correlations exceeding 90% to ECG and chest strap references for resting and sleep measurements. Apple's validation of background heart rate measurements during still periods, relevant to rest and sleep, shows 89% within 5 bpm of chest strap references. However, as a consumer-grade optical sensor, it is less precise than medical-grade oscillometric cuff-based devices like OMRON due to potential interferences from motion, fit, and perfusion; it is suitable for monitoring wellness trends rather than clinical substitution. A 2018 study of 50 participants during walking and found mean absolute percentage errors of 1.8% at rest and 2.3% during exercise, with validity decreasing at higher intensities above 140 bpm. In patients with , a 2019 validation against ECG showed clinically acceptable accuracy for 30-second averages during , with coefficients exceeding 0.9. A 2025 study in cardiac patients confirmed strong correlation (r=0.99, p<0.001) for heart rate during exercise when benchmarked against medical-grade devices. In contrast to the high accuracy of heart rate monitoring (typically with median errors below 5%), the Apple Watch's estimation of energy expenditure (calories burned) exhibits moderate to poor accuracy. A 2017 study by Stanford University researchers evaluating seven wrist-worn devices, including the Apple Watch, found that while heart rate was measured with errors below 5% for most devices, no device achieved an error below 20% for energy expenditure compared to gold-standard indirect calorimetry, with the best-performing device (the Apple Watch) having a median error of approximately 27%. A 2025 systematic review and meta-analysis of 56 studies reported a mean absolute percentage error of 27.96% for energy expenditure across diverse activities, user groups, and Apple Watch models, with all subgroups exceeding the 10% validity threshold for acceptable accuracy. These findings indicate that energy expenditure estimates, which rely on heart rate, motion data, and user profile inputs, are suitable as rough approximations for general wellness and fitness motivation but are not sufficiently precise for clinical, nutritional, or research purposes requiring accurate caloric measurement. Fall detection, introduced in Apple Watch Series 4 (2018), relies on accelerometer and gyroscope data to identify hard falls followed by motionlessness. A 2022 controlled study simulating falls in 22 older adults reported 77% sensitivity and 99% specificity against video-confirmed events, with a 1.7% false-positive rate in daily activities. Empirical data remains limited, with real-world deployment studies noting under-detection of certain fall types like forward falls without wrist impact, though specificity minimizes unnecessary alerts. Blood oxygen (SpO2) measurements using reflectance PPG show moderate correlation with clinical pulse oximeters but fall short of medical-grade precision. A 2023 study in 106 healthy adults found a Pearson correlation of 0.77 between Apple Watch Series 6 and finger oximetry, with mean SpO2 of 95.9% but 14% of readings below 95% due to motion artifacts and skin tone variations. Validation in chronic disease patients yielded 84.9% accuracy within ±2% of reference devices, though outliers persisted in low-perfusion states. A 2022 analysis concluded SpO2 readings do not meet pulse oximetry standards for clinical diagnosis, recommending against sole reliance for hypoxemia detection. Sleep stage tracking, enhanced in watchOS 9 (2022), uses accelerometer, heart rate, and respiratory data but exhibits discrepancies against polysomnography (PSG). A 2024 study comparing Apple Watch to PSG in 30 participants found 86% agreement for sleep-wake detection but overestimation of light sleep by 45 minutes and underestimation of deep sleep, with Cohen's kappa of 0.45 for staging. Apple's internal validation claims population-level performance aligned with actigraphy for total sleep time (mean error <10 minutes), yet peer-reviewed comparisons highlight limitations in distinguishing REM from light stages due to wrist-based sensing constraints.

Reported Outcomes and Limitations

The Apple Heart Study, involving over 419,000 participants conducted between 2017 and 2019, demonstrated that the Apple Watch's irregular pulse notification algorithm identified atrial fibrillation (AFib) with a positive predictive value of 84% when confirmed by ECG patch monitoring, with sensitivity reaching 98.3% for episodes lasting at least 30 seconds in notified users. Approximately 0.5% of participants received notifications, enabling early detection in cases where subsequent clinical evaluation confirmed the arrhythmia, potentially averting strokes through timely intervention. Independent validations have corroborated high specificity for AFib detection via the Watch's ECG feature, with one 2025 meta-analysis reporting overall diagnostic accuracy exceeding 90% in controlled settings. Fitness tracking outcomes show reliable heart rate measurement during rest and moderate exercise, with mean absolute percentage errors under 5% in cardiovascular patients. This outperforms energy expenditure estimates (calories burned), which exhibit higher inaccuracies, often ranging from 15% to 30% or more due to variability in metabolic assumptions and individual physiological differences. For example, a 2017 Stanford University study found that the best-performing wrist-worn device had an average error of approximately 27% in energy expenditure, with no device achieving less than 20% error. A 2025 meta-analysis of 56 studies reported a mean absolute percentage error of approximately 28% for energy expenditure across various activities, user demographics, and Apple Watch models. Step counting aligns closely with reference pedometers, achieving correlation coefficients above 0.95 in ambulatory studies, supporting motivational activity goals. Fall detection has alerted users to real incidents, with one controlled trial reporting 77% sensitivity for induced falls alongside 99% specificity, reducing response times in elderly cohorts. Blood oxygen saturation (SpO2) readings correlate within 2-3% of clinical pulse oximeters in normoxic conditions (>90% saturation), aiding in screening. Limitations include frequent false positives in AFib notifications, occurring in up to 66% of alerts among younger users without confirmed arrhythmia, prompting unnecessary medical consultations and heightened anxiety, as evidenced by surveys linking repeated alerts to diminished physical health confidence. A "sinus rhythm" result from the ECG app does not confirm the absence of atrial flutter, AFib (beyond the snapshot), premature beats, or other arrhythmias; does not assess overall heart health or guarantee always normal rhythm; and does not detect heart attacks, strokes, blood clots, high blood pressure, heart failure, or most arrhythmias including atrial flutter (which may show as inconclusive, sinus, or undetected). Heart rate accuracy degrades during vigorous motion or in darker skin tones due to optical sensor limitations, with errors exceeding 10% in high-intensity scenarios; minor discrepancies in heart rate, steps, or calories compared to finger-worn trackers are typical due to wrist versus finger sensor placement, where finger-based readings may lag slightly during intense activity reflecting differences in motion artifact susceptibility and real-time sampling. According to Apple Support, various factors can cause the Apple Watch's heart rate readings to be inaccurate, display unexpectedly high values, or intermittently cut out. These factors include wearing the watch too loosely, excessive arm movement during activities, tattoos on the wrist, exposure to cold temperatures, poor peripheral blood flow, and a dirty or obstructed sensor. Apple recommends wearing the device snugly yet comfortably on the top of the wrist to ensure proper contact with the skin, regularly cleaning the sensor, avoiding activities that involve vigorous arm swinging, and maintaining good skin contact. If the issues persist after following these guidelines, users should try restarting the Apple Watch, updating to the latest version of watchOS, or contacting Apple Support to check for potential hardware problems. Fall detection sensitivity drops to 4.7% for wheelchair users, yielding high false negatives, and SpO2 measurements show bias toward overestimation in individuals with higher melanin levels, as highlighted in lawsuits and validation studies citing root mean square errors up to 6.7%. Excessive tightness in wearing the device can cause pressure on wrist tissues or nerves like the median nerve, leading to temporary pain, numbness, or tingling similar to carpal tunnel syndrome symptoms; these typically resolve by loosening the fit or changing the band. Apple officially states that the Apple Watch and other Apple devices contain magnets and components that emit electromagnetic fields, which may interfere with implanted medical devices such as pacemakers and defibrillators. Apple recommends keeping these devices at least 6 inches (15 cm) away from the medical device (or 12 inches/30 cm when using a wireless charger), consulting a physician and the medical device manufacturer for specific guidance, and stopping use if interference is suspected. These devices are cleared for wellness screening, not diagnosis, and over-reliance without clinical corroboration risks misinterpretation, particularly given algorithmic thresholds optimized for population-level alerts rather than individual precision.

Reception and Impact

Sales and Market Dominance

The Apple Watch, launched on April 24, 2015, achieved rapid sales growth in its initial years, establishing Apple as the dominant player in the smartwatch market. By 2016, shipments reached approximately 11.4 million units, rising to over 18 million in 2017 amid expanding model lineups and health feature integrations. Annual shipments peaked around 50 million in 2023 before declining 19% year-over-year to 39.8 million in 2024, reflecting broader market saturation and economic pressures in key regions like . Apple maintained a leading market position with over 50% global share for much of its history, driven by ecosystem integration with users and premium pricing that commanded higher average selling prices than competitors. This market leadership is bolstered by the Apple Watch's exclusive integration with the iPhone ecosystem, requiring an iPhone for setup, full functionality, updates, and most features, which limits cross-platform competition and encourages retention within Apple's user base, despite competition from Android-based smartwatches. Apple previously explored Android compatibility for three years but abandoned it due to technical limitations, with no announced plans for support in 2026 or beyond. In Q2 , Apple's share stood at 49%, far ahead of Samsung's 15% and Garmin's 11%. However, the overall market contracted 7% in —the first annual decline—while Apple's share eroded slightly due to slower innovation cycles and rising competition from Android-based devices. By Q2 2025, overtook Apple in quarterly shipments, capturing the top spot amid strong performance in , though Apple retained significant premium segment dominance. Cumulative revenues from Apple Watch sales exceeded $100 billion by Q2 2025, underscoring its commercial success despite unit shipment fluctuations. This milestone, reported by Counterpoint Research, highlights the device's high-margin positioning, with average prices often exceeding $400, compared to lower-end rivals. Factors contributing to sustained dominance include loyalty among Apple's 2 billion-plus active device users and features like ECG monitoring, which differentiate it in health-focused markets, though analysts note vulnerabilities to regulatory hurdles and supply chain dependencies.

Innovations and Achievements

The Apple Watch pioneered consumer-grade electrocardiogram (ECG) functionality on a wrist-worn device, receiving FDA clearance in 2018 for detecting through the Series 4 model, marking the first such approval for a wearable. This innovation utilized a digital crown and back to generate single-lead ECGs comparable to medical-grade devices. Subsequent advancements included the Series 6's blood oxygen sensor in 2020, enabling SpO2 monitoring via red and infrared LEDs, and fall detection algorithms that analyze and data to alert emergency services. In 2024, the AFib History feature became the first digital tool cleared by the FDA to assess burden using long-term optical data, providing users with a weekly estimate of AFib occurrence time. Hardware evolution featured Apple's custom system-in-package (SiP) chips, starting with the S1 in 2015—a 28nm dual-core processor integrating GPS, , and sensors—and progressing to the S8 in 2022 with a 7nm supporting always-on displays and neural engines for on-device . The Series 9 introduced the double-tap gesture in 2023, detected via , , and neural processing unit, allowing pinch controls without touching the screen. sensing debuted in Series 8 (2022) for cycle tracking, using two sensors for baseline shifts accurate to 0.1°C. In September 2025, the FDA cleared a hypertension notification feature for Apple Watch, employing photoplethysmography (PPG) signals to identify elevated risks, with notifications triggered after consistent high readings. Market achievements underscore its dominance, with cumulative sales exceeding 195 million units since the 2015 launch, outpacing rivals in the category. Apple shipped 30.7 million units in alone, surpassing global Swiss watch exports of 21.1 million, and generated approximately $13 billion in revenue contribution to Apple's bottom line by 2025. Despite a 19% sales decline in amid broader market contraction, Apple retained leadership with 17.9% global share per IDC data. In the U.S., it commands unmatched popularity among smartwatches and fitness trackers. Patent filings emphasize digital data processing innovations, with over 1,000 grants by Series 10 reflecting core smart features.

Criticisms from Users and Analysts

Users have frequently criticized the Apple Watch's battery life, which Apple rates at approximately 18 hours for standard models under typical usage, but often falls short in real-world scenarios involving workouts, notifications, or software updates. For instance, owners of the Series 10 reported draining from near-full charge to critically low within hours of moderate activity, prompting complaints of "catastrophic" performance shortly after purchase in late 2024. Battery degradation over time exacerbates this, with devices like the Series 5 showing rapid drain even at 83% health after years of use, and post-watchOS 11 updates accelerating consumption by up to 10% per hour in idle states. Health and fitness tracking accuracy draws mixed empirical scrutiny from users and studies, with heart rate monitoring performing adequately during low-intensity walking but declining significantly during jogging or running due to motion artifacts in optical sensors. A 2025 meta-analysis of 56 studies affirmed reliability for resting heart rate and step counts but highlighted inconsistencies in energy expenditure estimates and higher-intensity metrics, attributing errors to factors like wrist movement and skin tone variability. Users report over-tracking exercise minutes, such as logging 300+ unintended minutes daily, which undermines motivational features like activity rings. Advanced sensors for ECG or blood oxygen, while FDA-cleared for specific uses, face doubts in broader validation, with one analysis estimating sleep apnea detection accuracy below 35% in preliminary tests, necessitating further clinical corroboration. The device's heavy reliance on a paired for setup, app syncing, and core functionalities limits standalone utility, rendering it effectively unusable without Apple's and frustrating non-iOS users or those seeking independence. Apple provides no official support for Android phones, and there are no announced plans for such compatibility, including in 2026. Limited workarounds exist for cellular models, such as initial setup with an iPhone followed by standalone use for basic calls, messages, and fitness tracking, but they sacrifice features like Apple Pay, Siri, reliable messaging, and full data syncing. High pricing, starting at around $399 for base models and escalating for cellular or premium variants, amplifies perceptions of overvaluation when compared to mechanical alternatives offering superior longevity without charging needs. concerns persist, as aluminum and stainless cases prone to scratches and finishes that wear comparably to mid-tier luxury watches, with users expecting 5-year lifespans often facing hardware failures or battery replacement after 2-3 years. Analysts have noted iterative updates yielding marginal gains, such as the Series 10's thinner and larger display in , yet critiquing the lack of substantive battery or breakthroughs, positioning it as "basically the same" amid stagnant competition in wearables. Budget-oriented models like the SE omit key health tools such as ECG, reducing appeal for comprehensive monitoring at a lower . Some reviewers and users advocate ditching the device for , citing distraction from constant notifications and failure to deliver promised life-changing insights beyond basic timekeeping.

Controversies

Patent and Intellectual Property Disputes

In January 2020, Masimo Corporation filed a lawsuit against Apple Inc. in the U.S. District Court for the Central District of California, alleging that Apple Watch models Series 4 and later infringed on Masimo's patents related to light-based pulse oximetry technology for noninvasive blood oxygen saturation (SpO2) measurement. Masimo claimed Apple had recruited its employees and misappropriated trade secrets starting around 2013 to develop the feature, which debuted in the Apple Watch Series 6 in September 2020. Apple denied the allegations, asserting that its technology was independently developed and that Masimo's patents were invalid or not infringed. The dispute escalated when Masimo filed a with the U.S. International Trade Commission (ITC) in June 2021, targeting the Series 6 and subsequent models for importing infringing products. In October 2023, the ITC ruled that Apple violated two Masimo (U.S. Patent Nos. 6,699,194 and 7,215,991) covering aspects of LED-based for blood oxygen monitoring, issuing a limited exclusion order banning imports of affected Apple Watches starting January 2024, with a 60-day stay. Apple appealed to the U.S. Court of Appeals for the Federal Circuit, which temporarily lifted the ban on December 27, 2023; to comply during , Apple released software-disabled versions of the Series 9 and Ultra 2 in the U.S. on January 18, 2024, omitting the blood oxygen feature. Model numbers ending in "LW/A" indicate Apple Watch units sold in the United States with the blood oxygen (pulse oximetry) feature disabled as a workaround for the Masimo patent dispute and related import restrictions. In July 2024, the Federal Circuit upheld the ITC's infringement finding but remanded for further review on patent validity. Apple countersued in August 2022 in the U.S. District Court for the District of , accusing of infringing three Apple patents (Nos. 10,827,360; 11,109,834; and D878,460) through its W1 , which replicated Apple Watch elements and hardware designs. On October 25, 2024, a federal jury found liable for infringing two of Apple's design patents, awarding Apple $250 in nominal damages, though Apple sought over $1.6 million and an . has challenged Apple's patents' validity via inter partes review at the Patent Trial and Appeal Board. In August 2025, following U.S. Customs and Border Protection's approval of Apple Watch imports with reinstated blood oxygen functionality via a redesigned configuration, sued the agency, arguing the modifications still infringed its patents. Separately, in 2019, AliveCor filed infringement suits against Apple, claiming Apple Watch's electrocardiogram (ECG) app and irregular heart rhythm notifications violated AliveCor's patents on single-lead ECG (e.g., U.S. Nos. 9,955,872 and RE48,124). The ITC initiated an investigation in 2022 and, in a final determination on an unspecified date in 2024, found Apple infringed two AliveCor patents, issuing a limited exclusion order with a $2 per-unit bond, though enforcement was suspended pending presidential review and potential appeals. Apple contested the ruling, filing petitions challenging AliveCor's validity and arguing non-infringement based on independent development of its ECG hardware introduced in the Series 4 in 2018. These cases highlight ongoing tensions over wearable innovations, with ITC remedies focusing on import restrictions rather than domestic sales bans.

Regulatory Interventions

The Apple Watch's electrocardiogram (ECG) feature, introduced with the Series 4 model on September 12, 2018, received De Novo classification and clearance from the U.S. (FDA) as a Class II for detecting and irregular heart rhythms in adults over 22 years old not previously diagnosed with the condition. This clearance, granted on December 11, 2018, required Apple to implement post-market surveillance and labeling restrictions prohibiting use for diagnosing other arrhythmias or in symptomatic users. In contrast, the blood oxygen () sensor, debuted in the Series 6 on September 15, 2020, was positioned as a general wellness tool rather than a diagnostic , exempting it from FDA clearance requirements since it does not claim to diagnose conditions like . In September 2025, the FDA cleared the Apple Watch Series 11's hypertension notification feature, which analyzes blood flow patterns via the optical heart sensor to alert users to potential chronic high blood pressure, marking it as the first wearable-based system for such non-invasive monitoring without a cuff. This clearance enables deployment in over 150 countries, including the U.S. and EU, subject to similar regulatory approvals elsewhere, and underscores the FDA's evolving scrutiny of wearables transitioning from fitness trackers to medical adjuncts. A significant regulatory escalation occurred in the U.S. International Trade Commission (ITC) proceedings initiated by Masimo Corporation, which alleged patent infringement on pulse oximetry technology integral to the Apple Watch's blood oxygen feature. On October 29, 2023, the ITC ruled that Apple violated Section 337 of the Tariff Act by infringing two Masimo patents (U.S. Patent Nos. 10,912,502 and RE48,982), prompting exclusion orders banning imports and sales of infringing Series 9, Ultra 2, and subsequent models. The ban took partial effect on December 26, 2023, but was stayed by the U.S. Court of Appeals for the Federal Circuit pending appeal; Apple responded by redesigning U.S.-bound units to disable the blood oxygen app via software, averting full enforcement while preserving imports. As of July 7, 2025, appeals continued, with Apple contesting the ITC's jurisdiction and Masimo defending the ruling's scope. In August 2025, Apple reintroduced a modified blood oxygen feature for U.S. users on Series 9, 10, and Ultra 2 via software update, claiming circumvention of the ITC patents through algorithmic redesign, though challenged this via lawsuit against U.S. Customs and Border Protection for allegedly permitting infringing imports. European regulators, under the Medical Device Regulation (MDR), have required compliance for ECG and similar features since May 2021, with Apple obtaining for diagnostic claims, but no equivalent import bans have materialized. These interventions highlight tensions between innovation in consumer wearables and enforcement of and medical standards, with the ITC case exemplifying trade-based remedies over traditional FDA oversight for non-medical features.

Privacy and Data Handling Concerns

The Apple Watch collects extensive biometric and location data through sensors including monitors, accelerometers, GPS, and blood oxygen sensors, which generate records of users' physiological states, movements, and positions. This data is aggregated in the Health app on paired iPhones and can be synced to , raising concerns about centralized storage of sensitive personal information vulnerable to breaches or unauthorized access. In , a third-party aggregator called GetHealth exposed over 61 million records from fitness trackers, including Apple HealthKit data containing names, birthdates, weights, heights, genders, and locations of Apple users, highlighting risks from ecosystem integrations despite Apple's controls. Such incidents underscore the challenges of via APIs like HealthKit, where third-party apps can request access to metrics, potentially leading to leaks if permissions are mismanaged. Legal challenges have emerged over Apple's data practices; a 2024 federal lawsuit alleges the company violated privacy laws by collecting diagnostic and usage from Apple Watches and other devices even after users disabled personalization features, claiming breaches of user agreements. Critics argue this reflects broader issues with opaque transmission to Apple servers for analytics, where users lack granular control over what is sent, exacerbating risks in a device that continuously monitors . Law enforcement access to Apple Watch data has also drawn scrutiny, with reports of police obtaining movement and location records via warrants, as seen in criminal investigations where step counts and GPS logs contradicted alibis. While Apple requires legal process for disclosures and encrypts data, the persistence of such records enables forensic use, raising civil liberties concerns about pervasive surveillance from wearables not designed with full evidentiary protections. Wearables like the Apple Watch face HIPAA-related vulnerabilities when integrated into healthcare, as fitness data lacks the stringent protections of , potentially exposing users to or misuse by insurers and employers if shared inadvertently. A 2023 review noted recurring breaches in wearables, including violations and biometric exploitation, with Apple devices implicated due to their market dominance and data richness. Apple mitigates some risks through on-device processing for features like ECG analysis, for iCloud health data under Advanced Data Protection, and user-granted app permissions, asserting no data sales or ad targeting. However, reliance on backups and server-side analytics persists, and independent evaluations, such as Mozilla's, rate the Apple Watch as having notable shortcomings due to ecosystem lock-in and limited transparency on data flows.

Environmental Claims Scrutiny

Apple has promoted certain Apple Watch models, beginning with the Series 9 and Ultra 2 released on September 12, 2023, as carbon neutral, asserting that their lifecycle are offset to zero through a combination of material sourcing, manufacturing processes, and carbon credits. These claims specify that qualifying aluminum-cased models with braided solo loop or sport bands achieve carbon neutrality by using 100% renewable electricity for production and assembly, low-carbon aluminum smelting, over 95% fiber-based packaging, and offsets covering the remaining approximately 25% of emissions via reforestation projects in and . The company states that recycled content claims, including up to 100% recycled rare earth elements in magnets and in batteries for later models like the Series 10 (September 2024), have been verified by independent third parties such as Global Services against established recycled content standards. However, these assertions have faced significant legal and analytical challenges regarding their validity and transparency. On August 26, 2025, the Regional Court of ruled that Apple's "CO2-neutral product" marketing for the Apple Watch was misleading under German consumer protection law, as the carbon offsets relied on temporary reforestation initiatives whose sequestration effects are not guaranteed long-term due to risks like or wildfires. The court prohibited Apple from using such claims in , citing insufficient evidence that the offsets permanently neutralize emissions, a decision stemming from a by the Verbraucherzentrale (German consumer advocacy group). In the United States, a class-action filed in February 2025 in the Northern District of alleges greenwashing, contending that Apple failed to independently verify the emission reduction efficacy of the offset projects and that the credits do not reliably compensate for the product's full lifecycle footprint, including supply chain and user-phase energy use. Critics argue that while Apple's direct reductions—such as shifting to 30-40% recycled or renewable materials in devices like the Series 9 and 11, which lowers virgin resource extraction impacts—are empirically supported by data, the reliance on offsets undermines the neutrality claim by deferring rather than eliminating emissions. Carbon credits from projects often face scrutiny for overestimation, as verified reductions may not materialize if projects underperform or emissions post-offset period, a causal issue highlighted in independent analyses questioning the permanence of such mechanisms. In response to these pressures, Apple omitted carbon neutral designations from the Series 11 announcement on September 9, 2025, and removed the label from packaging for affected models like the Ultra 3, despite maintaining progress toward broader 2030 goals of 100% recycled materials in key components. The has defended Apple's approach in legal briefs, emphasizing the rigor of its verified reductions over offsets alone, though the ongoing U.S. suit tests whether such hybrid methods meet consumer expectations for unmitigated neutrality. Overall, empirical data from Apple's reports show measurable declines in per-unit emissions through and clean energy—e.g., surpassing 60% global GHG reduction targets by April 2025—but the offset component introduces verifiable risks of impermanence, prompting regulatory interventions that prioritize direct emission cuts over compensated claims.

Model Comparisons

Technical Specifications

The Apple Watch integrates a custom system-in-package (SiP) that combines the processor, RAM, storage, radios, and sensors into a compact module. The original 2015 model used the S1 SiP with a single-core ARM-based processor operating at approximately 520 MHz, 512 MB RAM, and 8 GB storage. The Series 1 (2016) employed the S1P variant, retaining similar single-core performance but optimized for cost. Starting with Series 2 (2016), the S2 SiP introduced dual-core processing at up to 1 GHz, still with 512 MB RAM and 8-16 GB storage depending on GPS variant. Subsequent advancements included the S3 (Series 3, 2017) with a dual-core processor and W2 chip; S4 (Series 4, 2018) with 64-bit dual-core at 1.5 GHz, 1 GB LPDDR4 RAM, and 16 GB storage; S5 (Series 5, 2019) adding support; S6 (Series 6, 2020) with a 20% faster S5-derived core and U1 chip; S7 (Series 7, 2021) enhancing power efficiency; S8 (Series 8, 2022) introducing a 4-core Neural Engine for on-device ; S9 (Series 9, 2023) with a faster Neural Engine and double-tap gesture enablement; and S10 (Series 10, 2024) featuring a 64-bit dual-core processor, 4-core Neural Engine, and 64 GB storage for advanced health algorithms like detection. Apple does not officially disclose RAM amounts beyond early models, but teardowns confirm increases to support growing software demands. To illustrate generational differences, the first-generation model (2015) and Series 9 (2023) differ in key specifications as follows:
  • Display: First generation used a Retina OLED display with Force Touch; Series 9 features an always-on Retina LTPO OLED display with up to 2000 nits brightness.
  • Processor: First generation employed the S1 SiP (single-core); Series 9 uses the S9 SiP with a 64-bit dual-core processor and 4-core Neural Engine.
  • Health and Sensors: First generation included basic optical heart rate sensor, accelerometer, and gyroscope; Series 9 adds ECG, temperature sensing, high/low heart rate notifications, and irregular rhythm alerts.
  • Connectivity: First generation had no GPS and Bluetooth 4.0; Series 9 includes built-in GPS/GNSS, optional cellular, and Bluetooth 5.3.
  • Water Resistance: First generation was splash-resistant; Series 9 is rated swimproof to 50 meters.
  • Other Features: Series 9 supports double-tap gesture, crash detection, fall detection, and fast charging; first generation lacks these.
  • Battery Life: Both rated up to 18 hours, with Series 9 adding fast charging and low-power mode support.
  • Sizes: First generation available in 38 mm and 42 mm; Series 9 in 41 mm and 45 mm.
Display specifications emphasize brightness, resolution, and efficiency. Initial models featured displays: 38 mm at 272 × 340 pixels (~290 ppi) or 42 mm at 312 × 390 pixels (~303 ppi), with Ion-X strengthened glass or optional . Series 4 expanded to 40 mm (384 × 480, 326 ppi) and 44 mm (368 × 448, 326 ppi) with edge-to-edge design and 1000 nits peak brightness. Always-on displays debuted in Series 5 (2019) using LTPO technology for variable refresh rates down to 1 Hz. Series 10 introduced wide-angle LTPO3 panels in 42 mm (430 × 536, ~326 ppi) and 46 mm (496 × 616, ~326 ppi) sizes, achieving up to 2000 nits brightness for outdoor visibility and thinner 1 mm bezels. Case sizes evolved from 38/42 mm (pre-Series 4) to 40/44 mm (Series 4–7), 41/45 mm (Series 8–9), and 42/46 mm (Series 10), with Ultra models fixed at 49 mm (502 × 410, ~254 ppi) using front . Sensors form the core of health and fitness tracking, with consistent inclusion of a high-dynamic-range (up to 256 g-forces in Ultra models), , and across all generations. Optical sensors progressed from first-generation (original) to third-generation in Series 10, enabling irregular rhythm notifications. Electrical heart sensors for single-lead ECG arrived in Series 4 (), blood oxygen monitoring (SpO2) in Series 3 hardware but enabled from Series 6 (2020), skin temperature sensing in Series 8 (2022) for cycle tracking, and depth/water temperature gauges exclusive to Ultra models for diving up to 40 meters. Series 9 added on-device Siri processing via Neural Engine, while Series 10 incorporated a new for detection via breathing disturbances. GPS evolved from single-frequency L1 (Series 2) to dual L1/L5 in Series 10 for precision, with altimeters becoming always-on from Series 6. Battery capacity uses built-in rechargeable lithium-ion cells, rated for 18 hours of typical all-day use (e.g., 90 time checks, 90 notifications, 45 minutes workout, app use) in standard Series models, with fast charging from Series 7 (80% in 45 minutes). Low Power Mode extends this to 36 hours. Ultra models double normal use to 36 hours (72 in Low Power Mode) due to larger 564 mAh cells versus ~300 mAh in standard 42/46 mm cases. Actual life varies by usage, with early models like Series 1 achieving similar 18-hour ratings despite smaller optimizations. Connectivity includes (802.11b/g/n at 2.4 GHz early, adding 5 GHz from Series 6), (4.0 to 5.3), and NFC for from launch. GPS and optional LTE/ cellular appeared in Series 2/3, with support; (U1) from Series 6 aids Precision Finding. Materials comprise aluminum cases standard (anodized), optional or (Series 5+ and Ultra), with composites or in limited editions. Water resistance improved to 50 meters (ISO 22810:2010) from Series 2, 100 meters for Ultra.

Performance and Feature Evolution

The Apple Watch's performance advancements stem primarily from iterative upgrades to Apple's custom system-in-package (SiP) chips, which integrate CPU, GPU, memory, wireless connectivity, and sensor processing on a single die, reducing power consumption and enabling denser feature integration. The inaugural model, launched on April 24, 2015, featured the S1 SiP with a single-core processor running at approximately 520 MHz, supporting core functions like optical heart rate monitoring via green LED sensors, accelerometer-based activity tracking, and basic app execution, though early reviews noted lag in interface responsiveness due to the chip's 32-bit architecture and limited RAM. Battery life was rated at 18 hours under mixed usage, constrained by the device's 205mAh (38mm) or 273mAh (42mm) battery and always-on display limitations. Subsequent models introduced dual-core processors and architectural shifts. The Apple Watch Series 1 (September 2016) upgraded to the S1P SiP, a cost-optimized variant with a faster dual-core CPU, improving app launch times by up to 50% over the original while retaining the 18-hour battery rating. The Series 2 (September 2016) debuted the S2 SiP, adding a built-in GPS chip for independent tracking and 50-meter water resistance, with the dual-core processor enabling swim-proof sensing; real-world GPS accuracy improved fixes to within 3-5 meters compared to phone-dependent in prior models. Series 3 (September 2017) incorporated the S3 SiP with an enhanced W2 wireless chip supporting optional LTE connectivity, allowing cellular models to handle calls and streaming without an , though LTE variants consumed up to 20% more battery during data sessions.
SeriesRelease YearSiP ChipKey Performance UpgradesBattery Life (Rated)
Original2015S1 (single-core, 32-bit)Integrated sensors for and motion18 hours
Series 12016S1P (dual-core)50% faster app performance18 hours
Series 22016S2 (dual-core + GPS)On-device GPS, water-resistant HR sensing18 hours
Series 32017S3 (dual-core + W2 wireless)LTE option, improved connectivity18 hours
Series 42018S4 (64-bit dual-core @ 1.5 GHz)ECG waveform generation, fall detection via upgraded /18 hours
Series 52019S5 (64-bit dual-core)Always-on with LTPO for 30% less power draw18 hours
Series 62020S6 (64-bit dual-core, 20% faster)Blood oxygen sensing via / LEDs, U1 chip18 hours
Series 72021S7 (same as S6, refined)Faster charging (80% in 45 minutes), dust resistance18 hours
Series 82022S8 (minor efficiency gains)Temperature sensor for cycle tracking, 18 hours
Series 92023S9 (64-bit dual-core, 30% faster neural engine)Double-tap gesture via neural processing, on-device 18 hours
Series 102024S10 (thinner design, 4-core neural engine) detection, depth/water temp sensors, 2x faster charging18 hours (36 hours low power)
Series 112025S11 (enhanced efficiency) notifications, extended low-power mode to 38 hours24 hours (with optimized always-on usage)
The shift to 64-bit architecture in Series 4 (September 2018) marked a pivotal performance leap, with the S4 SiP's dual-core processor at 1.5 GHz enabling the first electrocardiogram (ECG) app, which generates single-lead waveforms by analyzing electrical signals from the digital crown and back sensors, achieving FDA-cleared accuracy for detection comparable to clinical devices in studies. Fall detection was also introduced, using a 32-bit ultra-low-power and improved to detect hard falls with 95% sensitivity in trials. Series 5 (2019) added an via low-temperature polycrystalline oxide (LTPO) tech, reducing refresh rates to 1 Hz for minimal power impact, while the S5 SiP maintained . Health feature evolution paralleled hardware gains. Blood oxygen monitoring debuted in Series 6 (September 2020) with the S6 SiP's red and infrared LEDs, measuring SpO2 levels via pulse oximetry with accuracy within 3-4% of medical-grade devices in controlled tests, alongside a 20% faster processor for real-time processing. Temperature sensing in Series 8 (2022) used the S8 SiP's high-precision sensor for basal body tracking, aiding fertility awareness with ±0.1°C accuracy. Series 9 (2023) leveraged the S9's double-tap-enabled neural engine for gesture-based controls, reducing interaction latency to under 100ms. Series 10 (2024) introduced sleep apnea notifications via machine learning on accelerometer data, detecting breathing disturbances with 89% sensitivity per Apple's validation, plus water depth and temperature sensing for diving up to 6 meters. The S10 SiP supported these with a thinner profile and faster charging, reaching 80% in 30 minutes. By Series 11 (September 2025), performance refinements focused on efficiency, with the S11 SiP enabling notifications through aggregated , activity, and oxygen data trends, and extending battery life claims to 24 hours under standard use (versus 18 hours prior) by optimizing power and background , though real-world tests indicate variability based on usage. Across generations, battery ratings held steady at 18 hours for standard models due to added features offsetting hardware efficiencies, but low-power modes in Series 10 and later extend to 36-38 hours by disabling and limiting workouts. Independent benchmarks confirm processor speed doublings every few years correlate with reduced app load times (e.g., from 2-3 seconds in Series 3 to under 1 second in Series 10), though throttling during intensive GPS+HR sessions remains a limitation in compact form factors.

References

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