Free Accessible Color Checker
Accessible design starts with readable text. NToolHub's accessible color checker tests any foreground and background color pair against the WCAG contrast rules and reports instantly whether it passes AA or AAA for both normal and large text. Designers, developers, and content teams use it to validate button colors, body copy, and brand palettes before shipping — right in the browser, with a live preview that renders your text exactly as users will see it.
Large text (18.66px bold / 24px+) needs 3:1 for AA. Normal text needs 4.5:1.
How to Use the Accessible Color Checker
- Pick a foreground color and a background color with the two color inputs.
- Read the AA and AAA verdicts for normal and large text in the result panel.
- Preview your combination on the live heading and body sample.
- Adjust either color until every check you need passes.
Features
The checker calculates the exact WCAG contrast ratio for your pair and evaluates it against the AA and AAA thresholds for both normal text (4.5:1 / 7:1) and large text (3:1 / 4.5:1). A live sample renders a heading and paragraph in your chosen colors so you can judge readability with your own eyes, not just the numbers. Both color inputs update the verdicts instantly as you drag.
Benefits & Use Cases
Product teams prove their interfaces meet accessibility standards before launch. Freelancers hand clients documented AA compliance for buttons and body text. Bloggers and newsletter authors make sure their color schemes stay readable for low-vision readers. Dark-mode designers catch washed-out combinations early. Anyone publishing text on the web ships with confidence instead of guesswork.
Tips
Aim for at least 4.5:1 on all body copy for AA compliance. Large text — 24px and up, or 18.66px and bold — only needs 3:1, which gives headings more creative freedom. Borders and icons also need 3:1. If a brand color fails, try darkening or lightening it slightly rather than abandoning the hue entirely.
Frequently Asked Questions
What does an accessible color checker do?
It tests whether a text and background color pair meets WCAG contrast rules, reporting the exact ratio plus pass or fail verdicts for AA and AAA.
What contrast ratio is required for WCAG AA?
Normal text needs at least 4.5:1. Large text — 24px, or 18.66px and bold — needs at least 3:1.
What is the difference between AA and AAA?
AA is the standard benchmark most laws and guidelines reference. AAA is stricter — 7:1 for normal text and 4.5:1 for large text — for maximum readability.
What counts as large text in WCAG?
Text that is at least 24px, or at least 18.66px (14pt) and bold. Both qualify for the lower 3:1 AA threshold.
Is the checker free, and is my data private?
Yes, it is completely free with no sign-up. All calculations run in your browser, so your colors are never sent to any server.
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