Developer & Design Tools
Color Contrast Checker
Instantly check color contrast ratios against WCAG 2.1 AA and AAA standards. Live preview, multiple input formats, color blindness simulation, and suggestions for accessible color pairs. Essential for designers and developers.
All calculations follow the official WCAG 2.1 relative luminance formula. Works entirely in your browser.
Why Color Contrast Matters
Over 8% of men and 0.5% of women have some form of color vision deficiency. Low contrast text makes content unreadable for millions of people and fails legal accessibility requirements in many countries. This checker gives you the exact numbers you need to pass audits and create truly inclusive interfaces.
How to Use the Results
- Normal body text should aim for at least AA (4.5:1).
- Headings and large text have more lenient requirements.
- UI elements (borders, icons, form controls) need 3:1 minimum for AA.
- Use the suggestion button when a pair is close but not quite there.
Frequently Asked Questions
What contrast ratios are required for WCAG AA and AAA?
For normal text: AA requires 4.5:1, AAA requires 7:1. For large text (18pt+ or 14pt bold): AA is 3:1, AAA is 4.5:1. UI components and graphical objects need at least 3:1 for AA.
Why does my color pass in one tool but fail here?
Different tools sometimes use slightly different rounding or sRGB linearization. We follow the official WCAG 2.1 relative luminance formula exactly for maximum accuracy.
Does it support alpha transparency?
For the most accurate results we recommend checking the actual computed colors after compositing. The checker works with opaque colors; use a color picker that shows the final RGB values.