Send usage data on Firefox mobile browsers

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  • Revision id: 127460
  • Created:
  • Creator: Joni
  • Comment: correction per product team. waiting for confirmation before RFL
  • Reviewed: No
  • Ready for localization: No
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Firefox for Android and Firefox for iOS 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 Firefox 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

What data is collected and sent to the adjust backend?

For a new install, Firefox 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 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, and do not include any information about which features of the application may have been used.

You can turn off this collection and reporting in the Settings menu in Firefox:
  • 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 below the screen on some devices or at the top-right corner 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 Telemetry and Firefox Health Report.