Firefox 2.0 will include code to optionally record “browser metrics,” or usage statistics, and send the information back to Mozilla for analysis. The goal is that this information will aid developers in choosing features, designing UI behavior, identifying web sites that can cause problems, and other important points of the user experience.
In order to track statistics of a single user across multiple browser sessions, the browser is assigned a unique identifier (client ID) to be sent along with data. This ID is a hash of the time the ID was generated and a random number. When metrics data are sent to the location defined in metrics.upload.uri, a
X-Moz-Client-ID HTTP header is sent containing this ID.
Possible values and their effects
This string contains a GUID sent with metrics data. (Not defined by default; created first time metrics data is compiled)
- This preference has no effect — nor is its value populated — if metrics.upload.enable is false.
First checked in
Has an effect in
- Mozilla Firefox (1.8 branch builds since 2006-03-21 built with metrics extension; 2.0)
- Bug 324558 - Build data collection service to gather browser metrics
- Bug 330712 - generate, store, and send a user id for data collection