Contrast Checker
Check color contrast against WCAG AA/AAA.
Good contrast keeps text and UI readable for everyone, including people with low vision. Aim for at least 4.5:1 for body text.
The quick brown fox jumps over the lazy dog
The quick brown fox jumps over the lazy dog
- Normal text AA · 4.5
- Normal text AAA · 7
- Large text AA · 3
- Large text AAA · 4.5
- UI components 3.0
All color conversions run locally in your browser — nothing is uploaded, stored or logged.
How it works
- 1 Choose a foreground (text) color.
- 2 Choose a background color.
- 3 Read the contrast ratio and AA/AAA pass/fail.
- 4 Follow the suggestions until it passes.
Common use cases
- Make sure body text meets WCAG AA (4.5:1).
- Check button and link colors for accessibility.
- Validate a brand palette before shipping.
- Avoid low-contrast text that's hard to read.
Frequently asked questions
Is my color data sent anywhere?
No. Every conversion and calculation runs entirely in your browser — nothing is uploaded, stored or logged.
What ratios do AA and AAA require?
AA needs 4.5:1 for normal text and 3:1 for large text (≥18.66px bold or ≥24px). AAA needs 7:1 and 4.5:1. UI components and graphics need at least 3:1.
How is the ratio calculated?
Using the official WCAG formula: (L1 + 0.05) / (L2 + 0.05), where L1/L2 are the relative luminance of the lighter and darker colors.
Is it really free?
Yes — free, with no signup, no watermark and no limits.