Fenix uses Mozilla’s telemetry service (Glean) to measure feature performance and engagement.

Glean pings and metrics

By using the Glean SDK, Fenix can send the pings the SDK owns and defines, as documented in the Glean SDK docs.

Additional metrics or pings defined by Fenix are documented in the Glean Dictionary.

Crash reporting

See here for details on crash reporting in Firefox for Android.