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Color & Design Tools

Contrast Checker

Check contrast ratio between foreground and background colors.

Use the tool

Use Contrast Checker to test whether a foreground and background color pair is readable enough for UI text, labels, links, and controls.

Use the tool

Calculate contrast ratio for text and background colors with WCAG scoring.

Contrast

8.42:1

Excellent

*****

AA normal

Pass

AAA normal

Pass

AA large

Pass

AAA large

Pass

Why use Contrast Checker

  • Check text and background pairs before shipping a design system color token.
  • Review CTA buttons, badges, table text, chart labels, and form controls for readability.
  • Audit brand colors against light and dark surfaces before implementation.
  • Document WCAG-style contrast results during accessibility review and QA.

About this tool

Color contrast for accessible UI

Contrast Checker compares foreground and background colors so designers and developers can catch low-readability text before it ships.

AA and AAA thresholds

WCAG-style checks commonly compare contrast ratios against AA and AAA thresholds for normal and large text. This gives teams a shared accessibility benchmark.

Check real UI states

Test default, hover, active, disabled, focus, and error states. A color pair that passes in one state can fail when opacity, borders, or backgrounds change.

Example usage

Input

Foreground #FFFFFF, background #2563EB

Output

Contrast ratio report with AA and AAA-style pass/fail guidance.

Practical guide for Contrast Checker

Best practices

  • Check color pairs in the actual UI state where they will appear.
  • Test text, icons, borders, charts, and disabled states separately.
  • Document passing color pairs as reusable design tokens.

Common mistakes

  • Checking only the primary button and ignoring hover, focus, and disabled states.
  • Using opacity that lowers contrast after a pair originally passed.
  • Treating decorative contrast failures the same as important text failures.

How this tool works

  1. Step 1

    Open Contrast Checker and review the default example input.

  2. Step 2

    Paste your own input or upload source data when required.

  3. Step 3

    Run Contrast Checker to generate output instantly in the browser.

  4. Step 4

    Verify the output using the preview and formatting helpers on the page.

  5. Step 5

    Copy the final result and continue with a related tool if needed.

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FAQ

What is a contrast ratio?

A contrast ratio measures luminance difference between foreground and background colors, commonly used to judge text readability.

What contrast ratio should normal text meet?

WCAG AA commonly expects 4.5:1 for normal text, while larger text has a lower threshold and AAA has stricter thresholds.

Should brand colors always pass contrast?

Brand colors used for text or important UI states need sufficient contrast. Keep low-contrast brand colors for decoration or large non-text areas.

Does contrast checking replace user testing?

No. It is a strong baseline, but real readability also depends on font size, weight, spacing, context, and user needs.