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Flake filter for unstable tests

Flake filter automatically detects and ignores unstable tests so they don’t block your build. Each unstable test includes a trace to help you identify what changed during capture.

How flake filter works

Chromatic renders each test multiple times to determine whether a visual change is genuine or the test is unstable.

When Chromatic detects an unstable test, it ignores the test automatically so the build isn’t blocked on a false positive. On the build page, actual changes appear at the top, while ignored tests are grouped separately in a collapsed section below.

Chromatic test results page showing a list of tests with changes, and collapsed group at the bottom saying 4 unstable tests are auto-ignored.

Automatically ignored tests won’t affect your baselines unless you accept them, and they won’t surface in the UI Review workflow. You can still deny an unstable test to force the build to fail.

Auto-ignores don’t persist across builds

Flake filter runs on each build to reevaluate whether a test is still unstable. When a test becomes stable, it automatically returns to the test suite.

Disable flake filter

You can turn off automatic ignoring for unstable tests from your project settings.

Flake filter enabled in project settings, with a button to disable it.

Frequently asked questions

Do auto-ignored tests count toward my snapshot usage?

Yes. Chromatic has to capture a snapshot for a test to determine whether the test is stable, so ignored tests still count toward your snapshot usage. However, even though Chromatic may render a test multiple times to detect instability, you are only billed for one snapshot.