Color Contrast Checker

WCAG 2.2 Level AA requires a contrast ratio of at least 4.5:1 for normal text and 3:1 for large text (≥24px, or ≥18.66px bold). User-interface components and meaningful graphics also need 3:1. Level AAA raises the bar to 7:1 for normal text and 4.5:1 for large text.

WCAG 2.2 is the latest W3C Recommendation, but most laws still cite an earlier version: the ADA Title II rule and the EU's EN 301 549 reference WCAG 2.1 AA, and US Section 508 references WCAG 2.0 AA. The AA contrast thresholds are identical across 2.0, 2.1, and 2.2, so meeting 2.2 AA also satisfies the 2.1 and 2.0 contrast requirements. APCA (Accessible Perceptual Contrast Algorithm) is proposed for the future WCAG 3, which is still a W3C Working Draft and does not name it — so it is not normative. Use the WCAG version your jurisdiction requires, and treat the APCA score here as an experimental preview.

WCAG defines no rounding for the contrast ratio, so a value of 4.49:1 does not meet the 4.5:1 AA threshold even though it looks close. This checker compares the exact computed ratio against the threshold.

It adjusts only the OKLCH lightness of the color you choose to change — text or background — and re-scores until the result meets your selected target, then returns the nearest passing value. It keeps your original hue, and its chroma wherever the result stays in sRGB — chroma is reduced only if a lightness change pushes the color out of gamut — so the suggestion stays on-brand. The returned hex is verified to pass after 8-bit rounding.

Yes. You can paste hex, rgb(), hsl(), or oklch() values. Because both WCAG and APCA are defined on sRGB luminance, out-of-sRGB colors are mapped into sRGB before scoring. Semi-transparent text is alpha-composited over the background first, since contrast formulas are defined for opaque pairs.