Free tool
WCAG Contrast Checker
Check if your color combinations meet WCAG 2.1 contrast criteria for text and graphic elements.
FAQ
The contrast ratio is a measure of the luminance difference between two colors, defined by WCAG (Web Content Accessibility Guidelines). It ranges from 1:1 (no contrast) to 21:1 (maximum contrast, black on white). A higher ratio means the text is more readable.
AA is the minimum recommended standard: 4.5:1 for normal text and 3:1 for large text (24px+ or 18.5px+ bold). AAA is stricter: 7:1 for normal text and 4.5:1 for large text. RGAA requires the AA level.
Large text is defined as text at least 24px (18pt) in normal weight, or at least 18.5px (14pt) in bold. These sizes benefit from a reduced contrast threshold because larger characters are easier to read.
You have several options: darken the text color, lighten the background, or use the automatic suggestion provided by our tool. You can also increase the text size beyond 24px to benefit from the AA Large threshold (3:1).
Yes, RGAA uses the same contrast ratios as WCAG 2.1 level AA. RGAA criteria 3.2 and 3.3 correspond to WCAG success criteria 1.4.3 and 1.4.11.