Telemetry Collection & Deletion

Firefox collects telemetry data by default. We collect this to help improve the performance and stability of Firefox. Telemetry data is made up of two data sets: interaction data and technical data.

What is interaction and technical data?

Interaction data includes information about your interactions with Firefox to us such as number of open tabs and windows, number of webpages visited, number and type of installed Firefox Add-ons and session length, as well as Firefox features offered by Mozilla or our partners such as interaction with Firefox search features and search partner referrals.

Technical data includes information about your Firefox version and language, device operating system and hardware configuration, memory, basic information about crashes and errors, outcome of automated processes like updates, safebrowsing and activation to us. When Firefox sends data to us, your IP address is temporarily collected as part of our server logs. IP addresses are deleted every 30 days. If you are interested, you can read more about how we handle your data in our in-depth documentation about our data platform.

We do not know about your specific interactions with Firefox. We just know the number of tabs a user had opened and how long they were opened.

Can I learn more about telemetry data collection?

Yes! You can read about our telemetry data collection by typing about:telemetry in the browser’s search bar. This page will show you the telemetry data being sent to Firefox for your current session. You can also see archived information.

If you want to more information about specific probes, we have made a probe dictionary that is publicly available for our users.

Any data collection or sharing adheres to our Firefox data collection policy.

How long do you keep telemetry data?

We keep telemetry data for 13 months.

How do I opt out or delete telemetry data?

You can opt out of sending any Firefox telemetry information at any time. If you opt out of sending telemetry data, we will also treat this as a request to delete any data we previously collected. Data will be deleted within 30 days after you opt out.

Telemetry

To opt out of sending any Firefox telemetry information:

  1. Click the menu button New Fx Menu Fx57Menu and select Options.Preferences.
  2. Select the Privacy & Security panel.
  3. Scroll to the Firefox Data Collection and Use section.
  4. Deselect the Allow Firefox to send technical and interaction data to Mozilla checkbox.

To learn more about what data Mozilla receives and how it's used, see Mozilla's Firefox Privacy Notice.

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