Color contrast checker
Calculate the contrast of two opaque colors and WCAG 2.2 AA/AAA text thresholds.
How to use
Enter opaque text/background colors and calculate. Read the ratio and each threshold result using your actual text size.
Try an example
Black #000000 on white #FFFFFF gives 21:1; the same color on itself gives 1:1.
Support & limits
WCAG 2.2: AA requires 4.5:1 for normal text and 3:1 for large text; AAA requires 7:1 and 4.5:1. Large means 18pt or 14pt bold. Decisions use the unrounded ratio; display rounds to four decimals. W3C references: Understanding SC 1.4.3 and SC 1.4.6.
Common questions
Does a pass mean a website fully meets WCAG?
No. This checks only the contrast ratio of two colors. Fonts, images, interactive states and other accessibility requirements need separate review.