Need to format JSON from an API response? The Wivrix Colour Contrast Checker (WCAG) is free, works in your browser, and takes seconds to use.
What this tool does
Check whether text and background colours meet WCAG AA and AAA accessibility standards. See the contrast ratio live and get the nearest passing colour when it fails.
Why use Wivrix?
Many online tools ask you to sign up, add a watermark, or upload your files to a server you cannot see. Wivrix is different:
- Private by design — Everything runs in your browser. Your files and input stay on your device — nothing is uploaded to Wivrix.
- Free — no account, no paywall, no file-size tricks
- Fast — open the page and start working
Step-by-step guide
- Enter your text colour and background colour as hex, rgb() or a basic colour name.
- Use the swatches to pick colours visually instead of typing them.
- Read the contrast ratio and the pass/fail result for each WCAG level.
- Check the live preview to see how the combination actually reads at both sizes.
Common uses
- Format json from an api response
- Decode a jwt during debugging
- Test a regular expression quickly
- Convert yaml config to json
Frequently asked questions
Do I need an account?
No. Open the tool and use it straight away.
Is the Colour Contrast Checker (WCAG) really free?
Yes. Wivrix tools are free to use. The site is supported by ads that load only after you consent.
Is my data safe?
Everything runs in your browser. Your files and input stay on your device — nothing is uploaded to Wivrix.
Try it now
Open the free Colour Contrast Checker (WCAG) and follow the steps above. If this guide helped, bookmark the tool or share it with someone who needs the same job done quickly.
Related tools
- Color Converter — see also our guide
- Color Palette Generator — see also our guide
- CSS Gradient & Shadow Generator — see also our guide
Ready to try it? Open the free Colour Contrast Checker (WCAG) — no sign-up needed.
Open Colour Contrast Checker (WCAG) →