Color Contrast Checker — WCAG 2.1 AA & AAA Accessibility Validator

What is WCAG Color Contrast?

The Web Content Accessibility Guidelines (WCAG) 2.1 define minimum contrast ratios to ensure text is readable for people with visual impairments, including color blindness. The contrast ratio is calculated using the relative luminance of the two colors, ranging from 1:1 (identical) to 21:1 (black on white).

WCAG defines two conformance levels: AA (minimum) requires a 4.5:1 ratio for normal text and 3:1 for large text (≥18pt or ≥14pt bold). AAA (enhanced) requires 7:1 for normal text and 4.5:1 for large text. All calculations are done locally in your browser.

Supported Color Formats

• HEX — #1a2b3c or shorthand #abc
• RGB — rgb(26, 43, 60)
• HSL — hsl(210, 40%, 17%)