The open-source accessibility rules engine almost every other tool is built on.
axe-core is Deque's JavaScript library that evaluates a rendered page against WCAG rules and returns violations with the element, rule and remediation guidance. It is deliberately tuned for zero false positives, and it powers Lighthouse, Chrome DevTools, Playwright's accessibility checks and most commercial scanners.
Best for
Free and open source
Open sourceFree tier: Everything, self-hosted
What drives the bill: Free and open source. You pay in engineering time and CI minutes.
Check current pricing on Deque Systems’s siteFigures are indicative and were last reviewed August 2026. Vendors change pricing often; confirm before you commit.
No reviews of axe-core yet. If you have used it in anger, yours would be the first.
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