Vérificateur de contraste (WCAG)
Vérificateur de contraste WCAG gratuit. Vérifiez le contraste entre deux couleurs — voyez le succès/échec AA/AAA pour le texte normal et le texte large. Pour la conception accessible et l'a11y.
Runs in your browserUpdated Apr 26, 2026
Contrast checker (WCAG)
The quick brown fox
jumps over the lazy dog · 14px sample
Ratio
17.85:1
AA · normal
Pass
AA · large
Pass
AAA · normal
Pass
AAA · large
Pass
Questions fréquentes
›What WCAG levels are checked?
Both AA and AAA, for normal text (≤17pt) and large text (≥18pt or ≥14pt bold).
›What ratio do I need?
AA: 4.5:1 normal, 3:1 large. AAA: 7:1 normal, 4.5:1 large. Most public sites target AA at minimum.
›How is contrast calculated?
Per WCAG 2.x: relative luminance of each color, then (lighter + 0.05) / (darker + 0.05). The result is a ratio from 1:1 (no contrast) to 21:1 (max).
›What about WCAG 3 / APCA?
Currently we use WCAG 2 ratios — the official standard for AA/AAA conformance. WCAG 3 / APCA is still a draft.
›Is the checker free?
Yes — fully free, no signup.