Android KitKat

Android KitKat is the codename for the eleventh Android mobile operating system, representing release version 4.4. Unveiled on September 3, 2013, KitKat focused primarily on optimizing the operating system for improved performance on entry-level devices with limited resources. It is the last version of Android to use the "Holo" interface. On July 24, 2023, Google announced that Google Play Services would no longer support KitKat in August of that year. The first phone with Android KitKat was the Nexus 5.

As of January 2025,^[update] 0.12% of Android devices run KitKat.

Android 4.4 "KitKat" was officially announced on September 3, 2013. The release was internally codenamed "Key lime pie"; but John Lagerling, director of Android global partnerships, and his team, decided to drop the name, arguing that "very few people actually know the taste of a key lime pie". Aiming for a codename that was "fun and unexpected", his team pursued the possibility of naming the release "KitKat" instead. Lagerling phoned a representative of Nestlé, who owns the Kit Kat brand and produces the confectionery (outside the United States, where it is produced by The Hershey Company under license), and quickly reached a preliminary deal for a promotional collaboration between the two companies, later finalized in a meeting at Mobile World Congress in February 2013. The partnership was not revealed publicly, or even to other Google employees and Android developers (who otherwise continued to internally refer to the OS as "KLP"), until its official announcement in September.

As part of the promotional efforts, Kit Kat bars in the shape of the Android robot logo were produced, while Hershey ran a contest in the United States with prizes of Nexus 7 tablets and Google Play Store credit.

The Nexus 5, developed by LG Electronics, was unveiled on September 30, 2013, as the launch device for KitKat.

Up to October 2017, Android 4.4 was still supported with security patches by Google for the source code.

Continuing on from the focus on improving visual performance and responsiveness on Android 4.1 "Jelly Bean", the main objective of Android 4.4 was to optimize the platform for better performance on low-end devices, without compromising its overall capabilities and functionality. The initiative was codenamed "Project Svelte", which Android head of engineering Dave Burke joked was a weight loss plan after Jelly Bean's "Project Butter" added "weight" to the OS. To simulate lower-spec devices, Android developers used Nexus 4 devices underclocked to run at a reduced CPU speed with only a single core active, 512 MB memory, and at 960×540 display resolution—specifications meant to represent a common low-end Android device.

A development tool known as ProcStats was developed in order to analyze the memory usage of apps over time, especially those that run background services. This data was used to optimize and decouple Google apps and services found to be inefficient, thus helping to reduce the overall memory usage of Android. Additionally, 4.4 was designed to be more aggressive in managing memory, helping to guard against apps wasting too much memory.