Contrast Colour Checker —
Free WCAG AA & AAA Test Online
Test any colour pair against WCAG AA and AAA contrast standards instantly. Free contrast colour checker — no signup, no limits, instant results for designers and developers.
Open the Free Contrast Colour Checker
Enter your text and background colour — get instant pass/fail for WCAG AA, AAA, AA Large, and AAA Large.
Check Colour Contrast Free →How to Check Colour Contrast for WCAG Compliance
Enter your text colour and background colour hex codes into the contrast checker. The tool instantly calculates the contrast ratio using the WCAG relative luminance formula and shows pass/fail for all four WCAG thresholds: AA (4.5:1 for normal text), AA Large (3:1 for large text), AAA (7:1), and AAA Large (4.5:1 for large text).
Use the Auto-fix button to get the nearest passing colour to your original. The colourblind simulation shows how your pair appears to people with Protanopia, Deuteranopia, and Tritanopia. Export your palette as CSS variables or Figma design tokens.
| Standard | Normal Text | Large Text |
|---|---|---|
| WCAG AA | 4.5:1 minimum | 3:1 minimum |
| WCAG AAA | 7:1 minimum | 4.5:1 minimum |
| ADA Compliance | Requires WCAG 2.1 AA | Requires WCAG 2.1 AA |
Contrast Colour Checker vs WebAIM
WebAIM's contrast checker is widely referenced and accurate. Web Asset Suite uses the same WCAG formula — the ratios are identical. The additional features here include a live webpage preview, colourblind simulation for three vision types, a palette contrast grid, and CSS/Figma export.
For designers working in colour systems, the palette grid is the most useful addition — it shows every combination of your brand colours in a single table, making it easy to identify which pairs pass and which need adjustment before publishing your design system.