WCAG color contrast checker
Enter a text and a background color to get the WCAG contrast ratio and see whether it passes AA and AAA for normal and large text.
- Runs in your browser
- No upload
- Result stays on your device
Privacy & limitsRuns in your browser. Nothing is uploaded.
Input content stays in this tab; Refentra does not upload or store it. Optional aggregate action counts are sent only with your usage consent. Clear the workspace when finished.
Supported profile: WCAG 2.2 opaque sRGB; AA normal/large: 4.5/3; AAA: 7/4.5. Large text: 18pt or 14pt bold.
Maximum text: 200,000 UTF-16 units; parser limits can be smaller. Worker time limit: 15 seconds (regex 1.5 seconds).
Check the input and the result
- Prepare and choose the operation
Enter opaque foreground and background colors, and compare the normal-text and large-text thresholds separately.
- Check a concrete example
Use this sample and compare the indicated result: #000000 / #ffffff → 21:1; #777777 / #ffffff → ≈4.48:1 < AA 4.5:1
- Check the output before you reuse it
Read the numeric ratio before the pass labels. A value near 4.5 has to meet the unrounded threshold.
Answers for this task
When is text large?
In WCAG, large text means at least 18pt, or 14pt bold. AA requires 3:1 for it, compared with 4.5:1 for normal text.
What should I check if the input fails?
Use a supported opaque color syntax. If a color is transparent, resolve it against the actual background before you compare.
Where does this tool stop?
A two-color WCAG 2.2 contrast check is not a complete accessibility audit. Gradients, images, focus visibility and context need separate checks.