Color Contrast Checker
Check text/background color contrast against WCAG AA and AAA accessibility standards.
Low-contrast text is one of the most common and most easily fixed accessibility failures on the web — it's easy for a design that looks fine on a designer's calibrated monitor to be genuinely difficult to read for users with low vision, color blindness, or simply anyone using a phone in bright sunlight. The Web Content Accessibility Guidelines (WCAG) define specific, testable contrast ratio thresholds precisely so this can be checked objectively rather than by eye.
This checker computes the exact WCAG 2.1 contrast ratio between a foreground (text) and background color, using the same relative luminance formula defined in the specification, and reports pass/fail against the AA and AAA standards for both normal and large text. AA requires a 4.5:1 ratio for normal text (3:1 for large text, defined as 18pt+ or 14pt+ bold), while the stricter AAA level requires 7:1 (4.5:1 for large text).
A live preview shows your actual color combination rendered as sample text, so you can see the real visual effect alongside the numeric ratio.
How to use Color Contrast Checker
- 1
Pick your text color
Choose the foreground (text) color.
- 2
Pick your background color
Choose the background color it will sit on.
- 3
Check the pass/fail badges
See the exact contrast ratio and whether it meets AA and AAA thresholds for normal and large text.
Features
- Computes the exact WCAG 2.1 contrast ratio formula
- Checks against AA and AAA thresholds for both normal and large text
- Live sample text preview using your actual colors
- Instant recalculation as you change either color
Frequently asked questions
Common mistakes to avoid
- Checking contrast only for body text and forgetting about smaller UI text like captions or form labels.
- Relying on how colors look on one monitor without verifying against the actual measured contrast ratio.
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