Color Contrast Checker
Check color contrast ratio against WCAG AA and AAA accessibility standards. Enter values for instant results with step-by-step formulas.
Reviewed by Daniel Agrici, Founder & Lead Developer
Reviewed by Daniel Agrici, Founder & Lead Developer
Formula
Contrast Ratio = (L1 + 0.05) / (L2 + 0.05) where L = relative luminance
WCAG 2.1 requires 4.5:1 for normal text (AA) and 7:1 for enhanced (AAA). Large text (18pt+): 3:1 (AA) and 4.5:1 (AAA).
Worked Examples
Example 1: Dark gray on white
Problem:#333333 on #FFFFFF
Solution:Contrast ratio ≈ 12.63:1
Result:12.63:1 (AAA Pass)
Reviewed by Daniel Agrici, Founder & Lead Developer · Editorial policy