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 |
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.