WCAG 2.1 AA/AAA & APCA Color Contrast Ratio Checker
Calculate exact WCAG 2.1 contrast ratios (`1:1` to `21:1`) and modern APCA perceptual lightness contrast (`Lc`) for normal text, large headings, and UI borders. 100% free, instant execution, dark mode supported, and zero registration required on TempoMailUSA.
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Overview & Usage
WCAG 2.1 AA/AAA & APCA Color Contrast Ratio Checker is a free online tool designed for wcag aaa and apca color contrast checker. Calculate exact WCAG 2.1 contrast ratios (`1:1` to `21:1`) and modern APCA perceptual lightness contrast (`Lc`) for normal text, large headings, and UI borders. It runs quickly and privately in your browser with instant copy and export options.
This tool runs with complete privacy in your browser. All inputs, calculations, and DNS verifications follow current web standards.
Technical Specifications
| Tool Name | WCAG 2.1 AA/AAA & APCA Color Contrast Ratio Checker |
|---|---|
| Category | Frontend UI & SVG |
| Processing | Client-Side (Browser) |
| Privacy | Private — No inputs are saved or tracked |
| Output Formats | Clipboard Copy, Text, and JSON |
How to Use WCAG 2.1 AA/AAA & APCA Color Contrast Ratio Checker
Enter your domain, IP address, text, or code into the input field above, or click one of the quick sample presets.
The tool processes your input locally in your browser in milliseconds without sending your data to any server.
Inspect the generated code, formatted results, and diagnostic details in the results panel.
Click the Copy button to copy the output directly to your clipboard, or download it to your computer.