Color Contrast

WCAG foreground/background contrast ratio。 Runs locally—nothing uploaded.

Foreground (text)

Background

Use large-text threshold (≥18pt bold or ≥24pt regular)

Sample Aa 中文 123

Contrast

17.06 : 1

WCAG 2.1: AAA

How to use & FAQ

Color Contrast: WCAG foreground/background contrast ratio. Runs instantly in the browser.

Free, no signup.

Do I need to sign up to use Color Contrast?▾

No. All Tools Ku features are free with no registration.

Does Color Contrast upload my data?▾

No. Processing happens in your browser; data is not uploaded to toolsku.com.

Accuracy?▾

Standard algorithms; verify critical decisions.

What calculations?▾

See page for supported scenarios.

Does it work on mobile?▾

Yes. For large files, use Wi-Fi for a smoother experience.

Can I download the result?▾

Yes. Copy text output or use the download button when available.