Contrast Checker
Samples
Contrast ratio
5.17
:1
Foreground
#FFFFFF
Background
#2563EB
How to use
- Enter foreground and background colors in hex format, then review the calculated ratio and WCAG pass/fail levels.
- Watch for borderline values near 3.0, 4.5, and 7.0 because tiny color tweaks can change compliance status.
- Verify by testing final UI states such as hover, disabled, and dark mode themes, not only default styles.
FAQ
What is contrast checker used for?
Contrast Checker helps teams validate readability and WCAG compliance before shipping design and frontend updates.
Is my data uploaded?
No. Processing runs locally in your browser.
Does this tool check WCAG AA and AAA?
Yes. It reports ratio thresholds for normal text, large text, and common UI component scenarios.
Introduction
A contrast checker helps you confirm text and background colors are readable across real UI states. It is useful when design handoff looks correct visually but still needs measurable accessibility validation.
What is contrast checker?
Contrast checker calculates luminance difference between two colors and returns a ratio such as 4.82:1.
That ratio maps directly to WCAG thresholds, which makes review decisions less subjective during QA and pull requests.
It also helps catch failures introduced by token updates, theme changes, or new brand palettes.
Key Features
Live ratio output makes it easier to iterate quickly while adjusting foreground and background values.
WCAG status breakdown for AA, AAA, normal text, and large text helps teams choose the right compliance target per component.
Preview blocks show practical readability so you can compare strict ratio math with actual text appearance.
Common Use Cases
- Validating button, link, and form-label colors before an accessibility audit.
- Checking dark mode token sets where low luminance differences often cause hidden regressions.
- Reviewing design system updates to confirm existing components still pass required WCAG levels.
Best Practices
- Test every semantic state, including hover, active, disabled, and error colors.
- Keep a minimum safety margin above thresholds to reduce failures after minor brand adjustments.
- Validate both body text and icon or border contrast because requirements differ by element type.