Send usage data on Firefox mobile browsers

Revision Information
  • Revision id: 135196
  • Created:
  • Creator: Joni
  • Comment: updated with Firefox Focus and Klar
  • Reviewed: Yes
  • Reviewed:
  • Reviewed by: heyjoni
  • Is approved? Yes
  • Is current revision? No
  • Ready for localization: Yes
  • Readied for localization:
  • Readied for localization by: heyjoni
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Firefox for Android, Firefox for iOS, Firefox Focus and Firefox Klar collect data about installations and retention using a third-party tracking framework called adjust. This helps Mozilla determine the origin of the installation by answering the question, "Did this user on this device install the application in response to a specific advertising campaign performed by Mozilla?"

This framework consists of a software development kit (SDK) built into Firefox and a data-collecting Internet service backend run by the German company adjust GmbH. The adjust SDK is open source and MIT licensed (see the github repository). You can learn more about the adjust SDK at https://docs.adjust.com.

What data is collected and sent to the adjust backend?

For a new install, the application sends an anonymous "attribution" request to the adjust servers. This request describes how the application was downloaded, for example, whether it was downloaded directly via the App Store or through a marketing campaign link. The data includes an advertising ID, IP address, timestamp, country, language/locale, operating system and app version.

Firefox for iOS, Firefox Focus, Firefox Klar and Android will also occasionally send anonymous summaries about how often the application has been used. These summaries only include information regarding whether the app has been in active use recently and when.

Additionally, Firefox Focus and Firefox Klar will also report what features of the application are being used. It will send an anonymous report containing the specific filters being selected and count how many times the search, browse and erase button is pressed. This is described in more technical detail in Install and event tracking with the Adjust SDK.


You can turn off this collection and reporting in the Settings menu:
  • Firefox for iOS: Tap the menu button at the bottom of the screen, followed by the Settings icon. (You might need to swipe to the left first). Turn the switch off next to Send Anonymous Usage Data.
  • Firefox for Android: Tap the menu button (either at the bottom right on some devices or in the upper right of the browser) followed by Settings (you may need to tap More first) . Tap on the Privacy section and remove the check mark next to Firefox Health Report.
  • Firefox Focus & Firefox Klar: Tap the settings button at the top right of the screen. If you are in the browser you may have to hit the Erase button first. Turn the switch off next to Send Anonymous Usage Data.