AbstractPrisma
Accessibility

Accessibility Contrast Checker

Check whether your text and background colors meet WCAG AA and AAA contrast requirements.

Colors

Contrast ratio

Ratio21.0:1
AA Normal Text
Pass
AAA Normal Text
Pass
AA Large Text
Pass
AAA Large Text
Pass

Preview

Sample text on your chosen background

The quick brown fox jumps over the lazy dog.

Sample body text at normal size. 0123456789

What is the minimum contrast ratio for accessibility?

The contrast ratio measures the luminance difference between text and background. WCAG guidelines set minimums so people with low vision can read: 4.5:1 for normal text and 3:1 for large text at level AA. Good contrast also helps reading in sunlight and improves usability for everyone.

WCAG minimums

  • Normal text: 4.5:1 (AA), 7:1 (AAA)
  • Large text (18pt+ or 14pt bold): 3:1 (AA)
  • UI components and icons: 3:1
  • Avoid light gray on white for small text

AbstractOS

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Build it in Prisma Studio with good contrast and readability practices from the start.

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How to check color contrast

  1. 1

    Set text and background

    Pick the text color and the background color you want to evaluate.

  2. 2

    See the contrast ratio

    The tool shows the ratio and whether it passes WCAG AA and AAA levels.

  3. 3

    Adjust until it passes

    Refine the colors until you reach the minimum contrast for good readability.

Frequently asked questions

What is the WCAG contrast ratio?

It is the relationship between text and background luminance. WCAG recommends at least 4.5:1 for normal text (AA).

What is the difference between AA and AAA?

AA requires 4.5:1 (normal text) and AAA requires 7:1, a stricter accessibility standard.

Why does contrast matter for SEO?

Good accessibility improves user experience, an indirect signal valued by search engines.

Contrast Checker for Web Accessibility and WCAG 2.1

Ensure inclusive design and readability testing with our online contrast checker. Verify that text and background color combinations meet WCAG 2.1 criteria (AA and AAA) for normal and large text. Essential for designers and frontend developers who want websites accessible to all users.

Why use this tool

  • Real-time color contrast testing - instant results
  • WCAG 2.1 compliance - AA and AAA for normal and large text
  • Inclusive design - Pass/Fail indicators by criterion
  • Web accessibility without paid tools - 100% free
  • Color pair preview with example text
  • Ideal for design systems and interface reviews

How to use

  1. Select the text color (foreground) and background color
  2. Check the contrast ratio and AA/AAA badges on the side
  3. Adjust colors until you get a Pass at all desired levels
  4. Use the preview area to validate readability in practice

Frequently asked questions

What is WCAG 2.1 and why does contrast matter?
WCAG 2.1 provides web accessibility guidelines. Color contrast ensures that text and backgrounds have sufficient difference for readability by people with low vision or in varying lighting conditions. AA (4.5:1 normal text) and AAA (7:1) are the most commonly used levels.
Is the tool suitable for inclusive design?
Yes. The readability test available here follows official methods for calculating relative luminance and contrast ratio. Use it to validate color palettes before implementing them in production and ensure your interface is accessible.
Do I need to register or install anything?
No. The checker works in your browser without data submission. Simply choose your colors and see the results - ideal for quick use in design and frontend development projects.