Firefox 58: Mozilla will collect only base Telemetry data (release channel)

Mozilla will change Telemetry collecting in Firefox fundamentally for users on the release channel; in short: only base Telemetry is collected in release channel versions.

Traditionally, Mozilla collected two sets of Telemetry data of its Firefox web browser. Base Telemetry data that was on by default and could be disabled by Firefox users, and extended Telemetry which was off by default for Firefox release builds and on by default for pre-release channels such as Beta or Nightly.

Firefox users can go to about:preferences#privacy to control the data collecting. The functionality was streamlined in recent versions of Firefox to reduce the Telemetry controls to just one setting (previously there were two).

You find the following three settings under Data Collection and Use in Firefox 58 (some of which are also in older versions of Firefox):

• Allow Firefox to send technical and interaction data to Mozilla (default on).
• Allow Firefox to install and run studies (default on).
• Allow Firefox to send crash reports to Mozilla.

The two major changes are that there is only one Telemetry control for Firefox (the first preference), and that there is one for Shield studies.

The aim of Shield Studies is to push features to a small selection of Firefox release users. These users test the new functionality or change and get a chance to provide feedback on the experience. Changes range from tiny ones like a different button color to new features.

Tip: You can load about:studies to list the studies that are run in the copy of Firefox at that time.

The good news for Firefox users who are on release versions of Firefox is that Mozilla will collect less data because it won't collect extended Telemetry data anymore on release.

For Firefox users, there is no significant change; the data upload setting users chose is respected as before. The opt-in for additional Telemetry data went away; instead we always collect less data on Firefox release.

Important Telemetry preferences

The following preferences are the core Telemetry controls that users can set on the about:config page or using a user.js file.

• datareporting.healthreport.uploadEnabled -- Main Telemetry preference that determines whether Telemetry data is collected and uploaded.
• toolkit.telemetry.enabled -- This preference determines the build. True means pre-release version of Firefox, false means release version of Firefox.
• nsITelemetry.canRecordBase -- Determines whether any Telemetry data can be collected. Default is true.
• nsITelemetry.canRecordExtended -- Reflects if Firefox is a pre-release build (true) or release build (false).

Check out the main tracking bug for additional information.