About

About a11ycontrast

A free contrast auditor that checks your entire palette against WCAG 2.2 and APCA — and suggests the nearest accessible fix — all in your browser.

Most contrast checkers test one foreground-on-background pair at a time. Real design systems have a dozen colors, and the failing combinations are usually the ones nobody thought to check. a11ycontrast takes your whole palette and builds the full matrix: every color as text on every other color as background, scored with both the WCAG 2.2 ratio (the standard auditors and laws use) and APCA Lc (the perceptual algorithm headed for WCAG 3).

For each failure it doesn’t just show a red X — it computes the nearest accessible color by shifting lightness the smallest amount needed to pass, so the fix still looks like your brand.

It’s built for indie developers, solo founders and designers who need to prove WCAG / ADA / European Accessibility Act compliance without paying for a full audit suite. There’s no backend: your colors are parsed and scored locally and never leave your device.