Accessibility Contrast Checker
Verify colour contrast against all WCAG 2.1 AA and AAA criteria for text, large text, and UI components.
Colour Selection
rgb(26, 26, 26)
rgb(255, 255, 255)
Presets
Contrast Ratio
17.40:1
| Criterion | Level | Required | Result |
|---|---|---|---|
Normal text < 18pt / < 14pt bold | AA | 4.5:1 | PASS |
Large text ≥ 18pt or ≥ 14pt bold | AA | 3:1 | PASS |
UI components & graphics Buttons, form fields, icons | AA | 3:1 | PASS |
Normal text < 18pt / < 14pt bold | AAA | 7:1 | PASS |
Large text ≥ 18pt or ≥ 14pt bold | AAA | 4.5:1 | PASS |
Accessibility Contrast Checker — WCAG 2.1 AA & AAA
Colour contrast is one of the most common accessibility failures on the web. This tool checks your colour pairs against all five WCAG 2.1 Success Criteria related to contrast: AA and AAA for both normal text and large text, plus AA for non-text elements such as UI components, form inputs, and informational graphics. The contrast ratio formula follows the WCAG relative luminance model, converting sRGB values to linear light before calculating. A ratio of 4.5:1 (AA normal text) is the minimum required by WCAG 2.1 Level AA — the standard required by law in many jurisdictions including the EU, UK, and US. The higher 7:1 ratio (AAA) provides excellent readability for users with low vision. Use the live preview to validate readability across text sizes and UI patterns.