Firefox for Android

Firefox for Android is a web browser developed by Mozilla for Android smartphones and tablet computers. As with its desktop version, it uses the Gecko layout engine, and supports features such as synchronization with Firefox Sync, and add-ons.

The initial version of Firefox for Android was codenamed Fennec and branded Firefox for mobile; it initially supported Maemo and Android before supporting MeeGo and Firefox OS as well. Support for Maemo was later dropped. In 2020, a redesigned version of Firefox for Android (codenamed Fenix, and also branded as Firefox Daylight) was released, which introduced a new internal architecture and user interface inspired by Firefox Focus, new privacy features, and switching to curated WebExtensions for add-ons.

Firefox for mobile, codenamed "Fennec", was first released for Maemo in January 2010 with version 1.0 and for Android in March 2011 with version 4.0. Support for Maemo was discontinued after version 7, released in September 2011. The codename Fennec comes from the fennec fox, a small desert fox (just as the Fennec browser is a small version of the Firefox desktop browser). Firefox for Maemo Beta 5, released in 2009, was the first version to have the official Firefox branding, with the Firefox name and logo.

Fennec uses the Gecko engine; for example, version 1.0 used the same engine as Firefox 3.6, and the following release, 4.0, shared core code with Firefox 4.0. Its features include HTML5 support, Firefox Sync, add-ons support and tabbed browsing. The browser's version numbering was bumped from version 2.0 beta to version 4.0 to more closely match desktop releases of Firefox since the rendering engines used in both browsers are the same.

Plugin support was initially disabled by default, removing compatibility with popular web content types such as Adobe Flash. In September 2011, Flash support was implemented in pre-release builds for pre-Honeycomb versions of Android. Flash support for Android 2.x and 4.x was enabled for most smartphones in version 14.0; later it was removed in version 56.0.

On June 27, 2019, Mozilla unveiled Firefox Preview (codename "Fenix"), a redesigned version of Firefox for Android based on GeckoView – an implementation of Gecko that is decoupled as a reusable library, intended to be used as an alternative to the default Android WebView component (based on Blink engine). GeckoView was first used by Firefox Focus, whose design influenced aspects of Fenix. It has a redesigned user interface with support for dark mode, a new "Collections" feature for saving sets of tabs, and includes Enhanced Tracking Protection (a configurable blocker for web trackers and third-party cookies) and a redesigned private browsing mode.

The Firefox for Android Beta channel was migrated to the Fenix branch in April 2020, and it was officially released to the stable channel in August 2020 as version 79, branded as Firefox Daylight. The last Fennec-based version was version 68, which was released in July 2019, and received bug and security fixes until July 2020.

Firefox Lite, formerly Firefox Rocket, was a lightweight free and open-source web browser developed by Mozilla Taiwan for Android smartphones and tablets. Initially released only in Indonesia, it was available in various emerging markets. With an APK size of 6.51 MB, it featured Turbo Mode (enabled by default), which blocked third-party content of web pages such as ads and trackers, and a toggle to disable web images, to speed page loads and use less mobile data. In addition, it had a private browsing mode, tabs, night mode, and the ability to screenshot the entire page. It used the built-in Android WebView as the browser engine. Due to release of the refreshed Firefox for Android and Firefox Focus, that contains Firefox Lite capabilities (except for the tiny size, that being the point of Firefox Lite) and replaced it, support for Firefox Lite ended on June 30, 2021.