WCAG Color Contrast Checker
Free WCAG color contrast checker. Verify AA/AAA compliance for accessible designs.
100% runs in your browser — no upload, no trackingHow to use
Enter a foreground and background color, then click Check to see the WCAG contrast ratio.
Example
#000000 on #ffffff → 21.00:1 (PASS AA & AAA)
FAQ
Is my data uploaded to a server?
No. Every tool runs entirely in your browser. Your input never leaves your device.
Is this tool free?
Yes, all DevToolbox tools are free to use with no account required.
Does it work on mobile?
Yes, the interface is mobile-friendly and responsive.
How accurate is the conversion?
We use standard, well-tested algorithms (Web Crypto, Intl, DOMParser). Results match common reference tools.