Getting started

If you are interested in extending data collection by adding new probes have a look at

• Adding a new Telemetry probe
• How to report Gecko Telemetry in engine-gecko via Glean

If you want to work with the telemetry code itself, for example to fix a bug, it is often helpful to start with these steps:

1. Have a look at about:telemetry to see which data is being collected and sent.

2. Increase the log level in about:config by setting toolkit.telemetry.log.level to Debug or Trace. This will show telemetry information in the browser console. To enable the browser console follow these instructions.

3. Run a local telemetry receiver, e.g. this one and set toolkit.telemetry.server to “localhost” (Like the next preference this needs a restart.)

4. Set toolkit.telemetry.send.overrideOfficialCheck = true, otherwise local debug builds will not send telemetry data. (Requires restart.)

More information about the internals can be found here.

Further Reading

• Telemetry Portal - Discover all important resources for working with data

• Telemetry Data Documentation - Find what data is available & how to use it