Online WCAG Color Contrast Checker - AA/AAA compliance, real-time preview
This is sample text to preview the contrast between foreground and background colors.
WCAG (Web Content Accessibility Guidelines) specify minimum contrast ratios between text and background. Level AA requires ≥4.5:1 for normal text and ≥3:1 for large text; Level AAA requires ≥7:1 for normal text and ≥4.5:1 for large text. These ensure readability for users with visual impairments.
Ratio = (L1 + 0.05) / (L2 + 0.05), where L1 is the relative luminance of the lighter color and L2 of the darker color. Luminance is computed from sRGB channel values. The ratio ranges from 1:1 (no contrast) to 21:1 (maximum: black on white).
WCAG defines large text as: bold text ≥14pt (18.5px) or normal text ≥18pt (24px). Normal text is anything smaller. Large text has lower contrast requirements since size itself improves readability.
AA: normal≥4.5:1, large≥3:1. AAA: normal≥7:1, large≥4.5:1.
(L1+0.05)/(L2+0.
05) where L1/L2 are luminances. Range 1:1 to 21:1.
Bold≥14pt or normal≥18pt. Lower contrast requirements for large text.