Developer
JSON Formatter / Validator
Validate, format and compact JSON without uploading your input.
Open tool ↗Color Contrast Checker
Calculate sRGB WCAG contrast ratio and AA/AAA text thresholds.
Maximum 200,000 characters. Input is not stored.
Ready. Use Ctrl/⌘ + Enter to run.
Completed and failed run counts are stored only on this device.
How to use this tool
Enter an opaque hex foreground color, and set the hex background. Read the exact computed ratio and the separate normal/large-text thresholds.
Supported input and limits
Only #RGB or #RRGGBB opaque sRGB colors. No alpha blending, images, gradients or font-size detection. Passing this check is not a full website accessibility certification.
Frequently asked questions
Is input sent to a remote server?
No. Parsing runs in a local browser worker. No URL is fetched and raw input is not stored.
What does this result prove?
This is a bounded local inspection aid. It does not verify a live server, a security policy or complete website accessibility.
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