In Firefox, the tracking protection feature is automatically enabled in standard mode. However, Amplitude will not be able to record events when this feature is switched to “strict,” or when a private browser window is being used. This feature blocks trackers for cross-site tracking; its main purpose is to protect user privacy when browsing across the web.
To read more about what tracking protection is and how it affects tracking, read Mozilla’s documentation here.
Because this feature is designed specifically to prevent cross-site tracking, it blocks the Amplitude SDK—Firefox blocks the network requests, which results in events failing ingestion.
The following errors will appear when tracking protection is enabled in the Firefox browser:
Failed POST request:
According to the engineering team here at Amplitude, the best solution is to build a proxy server and make the JS SDK point to it. Check out our documentation on how to create a proxy to learn more.