Firefox Focus is a free and open-source privacy-focused mobile browserbyMozilla, based on Firefox. It is available for Android[4][5] and iOS smartphones and tablets.[6][7] Its predecessor, Focus by Firefox, was released in December 2015 as a tracker-blocking application which worked only in conjunction with the Safari mobile browser on iOS.[8][9] It was developed into a minimalist web browser in 2016 but retained this background blocking functionality.[10]
The Android version of the browser was first released in June 2017 and was downloaded over one million times in the first month.[11] As of January 2017, it was available in 27 languages.[12] The version released for German-speaking countries has telemetry disabled and is named Firefox Klar to avoid ambiguity with the German news magazine FOCUS.[13][14]
Firefox Focus is designed to block online trackers, including third-party advertising, with the end goal of both improving browsing speed and protecting users' privacy. Content blocking is achieved using the Disconnect block lists.[15][16] The blocking of third-party trackers (except "other content trackers") is enabled by default. In the other Firefox browsers, users have to enable the tracking protection feature inside the browser preferences manually.[17] Users can also view types of trackers on a page by tapping on the shield icon next to the URL bar. A panel will pop-up and shows what kind of trackers are on that page: ad trackers, analytics trackers, social trackers or content trackers.[18]
On December 20, 2018, Mozilla announced that Firefox Focus now checks all URLs against the Google Safe Browsing service to help prevent people from accessing fraudulent sites.[19]
To bypass content-blocker restrictions from Apple, Firefox Focus uses the UIWebView API on iOS devices.[20] On Android, it used the Blink engine in version 6.x and earlier, and it has used GeckoView since version 7.0.[21]
Firefox Focus can be set as content-blocker in the Safari web browser options.[22] After activating the Safari integration in the Firefox Focus settings, it will disable trackers automatically in the background when browsing using the Safari browser.
Pressing the trash icon while browsing will delete all session data, and return to the start screen (i.e. display the customisable search bar). Tabs can be opened by long-pressing a URL on a website. Favourite links can be set on the home screen of the device.
Firefox Focus contains a option called telemetry. By activating it, users can allow Mozilla to collect and receive non personal-identifiable information to improve Firefox.[23] Due to privacy concerns, telemetry of Firefox Klar is disabled by default.[24]
Beginning July 2018, Firefox Focus was preinstalled on the BlackBerry Key2 Android smartphone as part of the application Locker.[25][26]
October 15, 2018, Mozilla announced that Firefox Focus is being updated with a new search feature and visual design. That means the browser will conceptually tell users about its features and options.[27]
There are some minimum hardware requirements to remove tracking contents. The mechanism needs hardware that can handle the extra load of content blocking so it only works on 64-bit devices running iOS 9 and above including:[28]
iPhone 5s and newer
iPad Air and newer
iPad mini 2 and newer
iPod touch from the 6th generation
Apple Vision Pro
As of February 2021[update], iOS 11.4 or above is required to download Firefox Focus on the App Store.[29]
^Telemetry Readme - Firefox Focus on GitHub "Builds of "Focus for Android" have telemetry enabled by default ("opt-out") while builds of "Klar for Android" have telemetry disabled by default."
