It's helpful for Mozilla's engineers to be able to measure how Firefox behaves in the real world. The Telemetry feature provides this capability by sending performance and usage info to us. As you use Firefox, Telemetry measures and collects non-personal information, such as memory consumption, responsiveness timing and feature usage. It then sends this information to Mozilla on a daily basis and we use it to make Firefox better for you.

Telemetry is an opt-in feature. This means that you specifically need to tell Firefox to collect and send this information to us. For more about what kind of information is collected and how it's used, see our privacy policy.

How do I opt-in or opt-out of sending performance data?

When you install or update Firefox you may be presented with the following message that lets you turn the Telemetry feature on:

"Will you help improve Firefox by sending anonymous information about performance, hardware characteristics, feature usage, and browser customizations to Mozilla?"

You can also turn this on and off at any time with these steps:

1. In the Menu bar at the top of the screen, click Firefox and then select Preferences or Settings, depending on your macOS version.Click the menu button and select Settings.
2. Select the Advanced panel.
3. Select the General tab.
4. Check or uncheck the box next to Submit performance data

   

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