Test Flake Rate - CI/CD Glossary Definition
Test flake rate is the fraction of test runs that fail non-deterministically on unchanged code, typically measured as flaky failures divided by total runs over a window. It quantifies how much you can trust a green build.
Why measure it
A rising flake rate erodes signal: developers start ignoring red builds. Tracking flake rate per test lets you quarantine or fix the worst tests instead of reflexively retrying everything.
In CI
Compute flake rate by detecting tests that pass on retry after failing on the same commit. Teams running on platforms like Latchkey use this to separate genuine regressions from transient infrastructure noise.