Finch is Google’s internal A/B testing and feature experimentation framework used across Chrome and other Google products. In the context of WebRTC, Finch is used to gradually roll out new features, test different implementations, and gather performance data from real users.
When a new WebRTC feature or optimization is being developed in Chrome’s libWebRTC implementation, it typically goes through a Finch experiment before being enabled by default. This allows Google’s WebRTC team to test the change on a small percentage of users, monitor for regressions, and gradually increase the rollout.
How Finch relates to Field Trials
Finch works in conjunction with Field Trials, which are the mechanism by which features are toggled on or off. Finch controls which field trials are enabled for which users, while field trials define the actual feature flags. Developers can override field trials locally using chrome://flags or command-line switches.
Impact on WebRTC developers
Finch experiments can sometimes cause inconsistent behavior between Chrome users, as different users may have different WebRTC features enabled.
