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Welcome to the Experimenter documentation hub, your central resource for A/B experiments and feature rollouts in Firefox Mobile and Desktop. You should find these documents helpful if you are:

  • A product manager and you have a hypothesis you want to test or a feature you'd like to safely release.
  • An engineer who needs to implement an experiment or feature rollout in your client
  • A data scientist helping to design and interpret experiment results
  • A Mozilla leader who would like insight into completed and ongoing experiments and rollouts.

What is covered here?

These documents are specific to the Mozilla experimentation program known as Nimbus. Nimbus experimentation and support is currently available for our Firefox Desktop and Mobile browser applications.

Our platform code is all open-source however, we do not offer support or services to 3rd party consumers. Some documentation links may only be available to Mozilla employees and NDA contributors.

What other tools exist

The following projects have bespoke tools for experimentation. These are not included as part of this documentation with the exception of a migration guide from Normandy to Nimbus for engineers.

  • Firefox Desktop (legacy experimentation): Normandy
  • Mozilla Websites (a/b experiments): Bedrock
  • Firefox Accounts (limited content server): Fxa docs

About these docs

This website is built using Docusaurus. If you'd like to edit or add to them, check out the Contributing page.