Color Contrast Checker
WCAG 2 contrast ratio and AA/AAA pass-fail.
Rated 4.7 out of 5 based on 340 reviews
How to use color contrast checker
- Fill the fields or paste input in this tab.
- Set every option that changes the result, not only the defaults.
- Read the output. Invalid input shows an error in the status line.
- Copy or download the result. Nothing is sent to CZNull.
Color Contrast Checker
Color Contrast Checker
| Where it runs | This browser |
|---|---|
| Upload | None |
| Network | No request to compute the result |
| Limit | Invalid input stays on the page as an error |
What color contrast checker does
Relative luminance follows WCAG 2 sRGB. AA normal 4.5:1, AA large 3:1, AAA normal 7:1.
How this page works
All options on the form are sent into the local engine. WCAG 2 contrast ratio and AA/AAA pass-fail. Results never leave this device to be computed.
Limits and related pages
Stay on this URL for this job. Sibling tools in the same group cover nearby jobs without mixing formulas. Open the category hub if you need a different input set.
Questions
Does this page upload what I type?
No. The work runs in the page you opened. CZNull does not receive the input.
Can I recover the original from a hash or checksum?
No. Digests and CRC values are not encryption. This page will not reverse them.
Is encoding the same as encryption?
No. Encoding such as hex, Base32, and Base64 is reversible without a secret.
What happens on invalid input?
The status line shows the error. The previous result is cleared.