WCAG Contrast Checker
Sample text – preview
Contrast ratio:0:1
AA – normal text (≥ 4.5):—
AA – large text (≥ 3):—
AAA – normal text (≥ 7):—
AAA – large text (≥ 4.5):—
Calculated per WCAG 2.x (relative luminance). “Large text” = from about 18 pt or 14 pt bold.
Check colour contrast per WCAG
Good contrast between text and background determines readability and accessibility. The checker calculates the contrast ratio per the Web Content Accessibility Guidelines (WCAG) and instantly shows which levels are met.
- Contrast ratio: Ranges from 1:1 (no contrast) to 21:1 (black on white).
- Level AA: At least 4.5:1 for normal, 3:1 for large text – the usual legal benchmark.
- Level AAA: Stricter, at 7:1 and 4.5:1.
- Large text: from about 18 pt (24 px) or 14 pt bold (about 19 px).