Test your text and background colors against WCAG 2.1 Level AA standards. Instantly check 4.5:1 and 3:1 contrast ratios. No signup required. Trusted by 5000+ designers worldwide.
Welcome to the AccessiTool Color Contrast Checker — your free tool for testing text and background color combinations against WCAG 2.1 Level AA standards. Whether you're a designer, developer, or business owner, our color contrast analyzer helps you ensure your website is accessible to people with visual impairments.
With our free online contrast checker, you can instantly test any color combination. Just pick a foreground (text) and background color using the color pickers above, and our tool will calculate the contrast ratio and tell you if it passes WCAG 2.1 AA or AAA standards. It's that simple.
Color contrast is the difference in brightness between text and its background. WCAG 2.1 AA requires a minimum contrast ratio of 4.5:1 for normal text and 3:1 for large text. Our contrast ratio checker helps you test your colors instantly.
Use the color pickers above to test your text and background colors against WCAG 2.1 AA standards. No signup required.
Color contrast refers to the difference in light between foreground (text) and background colors. In web accessibility, it's one of the most critical factors for ensuring that people with low vision, color blindness, or reading on mobile devices can read your content.
WCAG 2.1 guidelines require a minimum contrast ratio of 4.5:1 for normal text and 3:1 for large text (18pt or 14pt bold). Low contrast is the most common accessibility violation, affecting users with low vision, color blindness, or reading on mobile devices in bright sunlight.
Our free WCAG contrast checker calculates the relative luminance of your chosen colors and instantly tells you if they meet WCAG 2.1 standards. Just pick a foreground and background color using the pickers above — the tool handles the math.
Minimum ratio: 4.5:1 — Required for body text, paragraphs, and small icons. Common failures: light gray text on white backgrounds (#888 on #FFF fails). Our contrast ratio checker highlights these instantly.
Minimum ratio: 3:1 — Applies to headings (18pt / 24px) or bold text (14pt). Use our color contrast analyzer to verify headline contrast without guesswork.
For higher accessibility, aim for 7:1 (normal text) and 4.5:1 (large text). While not mandatory for ADA/EAA, achieving AAA can differentiate your brand and reduce legal risk from plaintiffs who test for superior accessibility.
Use our color contrast checker to test your brand colors against WCAG 2.1 AA standards. No signup required.
No signup. Instant results. WCAG 2.1 AA.
The WCAG contrast checker standards define three levels of compliance:
AA compliance is required by ADA, EAA, Section 508, HHS, and most accessibility laws. AAA compliance is recommended for enhanced accessibility but not mandatory.
Under ADA Title III, websites must be accessible to people with disabilities. While the ADA doesn't specify exact technical standards, courts consistently reference WCAG 2.1 Level AA, which includes color contrast requirements:
ADA color contrast requirements apply to all text, buttons, form fields, and meaningful graphics. Non-compliance can result in lawsuits with settlements ranging from $10,000 to $50,000+.
Approximately 1 in 12 men (8%) and 1 in 200 women (0.5%) have some form of color blindness. That's over 300 million people worldwide. When checking color accessibility for color blindness, consider:
Test colors for accessibility by simulating color blindness using our color accessibility test tool.
AA & AAA standards
Instant results
See the contrast
Understand the legal framework behind web accessibility
Everything you need to know about color contrast, WCAG compliance, and accessibility testing.
4.5:1 is the minimum contrast ratio for normal text under WCAG 2.1 Level AA. This is the standard required by ADA, EAA, and Section 508. Use our free color contrast checker to test your colors instantly.
3:1 is the minimum contrast ratio for large text (18pt / 24px and above, or 14pt / 18.5px bold). Test your heading colors with our contrast ratio checker.
Use our WCAG color contrast checker. Enter your foreground and background hex codes, and the tool will instantly calculate the ratio and tell you if it passes WCAG 2.1 AA or AAA.
AccessiTool's color contrast analyzer is 100% free, supports WCAG 2.1 and 2.2, includes color blindness simulation, and works in any browser. Compare with WebAIM →
A contrast ratio is a number between 1:1 (no contrast) and 21:1 (maximum contrast, black on white). WCAG requires 4.5:1 for normal text. Test your colors now →
Yes. Poor contrast increases bounce rates. Lower bounce rates and longer dwell time are positive SEO signals for Google. Learn more →
ADA color contrast follows WCAG 2.1 Level AA: 4.5:1 for normal text, 3:1 for large text. Full ADA Title III Guide →
Section 508 color contrast follows WCAG 2.1 Level AA. Full Section 508 Guide →
AAA compliance requires 7:1 for normal text and 4.5:1 for large text. Full WCAG Guide →
Use our ADA compliance checker which includes automated color contrast testing across your entire website. Scan your website →
WebAIM is simple; AccessiTool offers color blindness simulation, PDF reports, and integration with other tools. Full Comparison →
White contrasts best with dark colors — black, dark blue, dark gray. Black on white provides 21:1 contrast — the highest possible. Full White Contrast Guide →
The best colors that contrast with blue are white, yellow, orange, and dark gray. White on dark blue provides 14:1 contrast. Full Blue Contrast Guide →
White on red (4.5:1) or red on white (4.5:1) — both pass WCAG AA. Avoid red on black — it fails (2.5:1). Full Red Contrast Guide →
AODA follows WCAG 2.1 Level AA: 4.5:1 for normal text, 3:1 for large text. Full AODA Guide →
Still have questions? Contact our team or test your colors now
Testing tools available in 5 languages