Text contrast checker
Check the luminance contrast of a text and background color pair. Passing this check alone does not make a page accessible.
Your inputs
Start with the example values, then replace them with your own. For tables, keep the vertical bar separators and use a dot for decimals.
Contrast ratio is only one accessibility check. Text size, weight, focus visibility, interaction and the full page still need evaluation.
Tool inputs are processed in your browser and are not submitted by this tool. Existing site analytics and advertising services have their own privacy terms.
Result and workspace
Use the start button to open your result or activity.
How it works
Convert sRGB channels to linear light, compute relative luminance, then contrast = (lighter + 0.05) / (darker + 0.05).
Worked example
These sample results use the original example inputs in the form. They do not change when you edit your inputs; your own result appears in the workspace.
- Contrast ratio: 4.9773
| Criterion | Result |
|---|---|
| Normal text AA | Pass |
| Large text AA | Pass |
Read the result carefully
Results depend on the values and assumptions shown above. Change one input at a time to see its effect. A blank or unavailable result means the data does not support a calculation; it is not zero.