Design

WCAG Contrast Checker

Verify accessible color pairs before you ship UI. Processing stays on your device — no upload, no account.

How to use WCAG Contrast Checker

  1. Pick text and background colors.
  2. Read the contrast ratio.
  3. See AA/AAA results for normal and large text.

Why use this free contrast checker tool?

  • All processing happens locally in your browser. Your files are never uploaded to a server.
  • WCAG 2.x relative luminance.
  • Live preview swatch.
  • Normal + large text checks.

Technical details

Implements the WCAG relative luminance and contrast ratio formulas on sRGB hex/RGB inputs.

WCAG Contrast Checker FAQ

Uploaded?

No. All processing happens locally in your browser. Your files are never uploaded to a server.

Large text?

18pt+ or 14pt bold roughly — UI labels may differ; check WCAG definitions.

Alpha / opacity?

This tool targets opaque colors.

APCA?

This build reports classic WCAG contrast ratios.

Related free converters

More private browser tools people use with contrast checker.