Contrast checker
Check the contrast between text and background colors.
- 1Add input
- 2Adjust settings
- 3Get your result
Tool input and files are processed in this browser without being uploaded.
Before you start
Compute the WCAG sRGB contrast ratio after alpha-compositing onto an explicit opaque background. Thresholds apply to this color pair only, not to whole-site accessibility compliance.
How to use this tool
- Enter a text color and a background color, or load the example to try them.
- Review Opaque compositing background before selecting “Check contrast”.
- Review the ratio, effective colors and AA/AAA text thresholds; copy a color or download the JSON result.
Supported inputs and limits
Pasted text is limited to 1 MiB; review the result before using it.
Worked example
Example input
Text #000; background #fff
Example options
{}Example output
{
"ratio": 21,
"foreground": "#000000",
"background": "#ffffff",
"AA_normal": true,
"AA_large": true,
"AAA_normal": true,
"AAA_large": true
}When something does not work
Use the documented input format and keep values within the displayed limits. Review the result before using it in another document or application. Editing the input marks the previous result as stale; a failed run clears it.
Frequently asked questions
Are my files uploaded?
No. Files and tool input are processed in your browser. Moving around the site can keep a temporary workspace in the same tab. Refreshing or closing the tab clears it, so download results you want to keep.
What should I check in this result?
Compute the WCAG sRGB contrast ratio after alpha-compositing onto an explicit opaque background. Thresholds apply to this color pair only, not to whole-site accessibility compliance.
Documentation & further reading
Related tools
Color converter
Same color. A different format.
Gradient maker
Find a blend you love. Copy the CSS.
Palette and color mixing
Generate rule-based palettes or compare weighted RGB color mixtures.
CSS shadow and radius
Compose layered shadows with optional individual border-radius values.