Continuous integration (CI) accessibility testing wires an automated scanner, commonly built on axe-core or Pa11y, into the same pipeline that already runs a project’s automated tests, so every pull request or build is automatically checked for common accessibility regressions before it merges or deploys.
This does not replace manual and screen reader testing, but it is highly effective at preventing already-fixed issues from silently reappearing, and at catching the most common, easily detectable problems, like missing alt text or insufficient contrast, before a single line of broken code reaches production.