Contrast Checker — WCAG AA & AAA Color Testing

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Will real humans be able to read this? Test any text/background pair against WCAG AA and AAA.

Text color

Background color

Readability is respect.

How to use this tool

1. Pick your text color and your background color.
2. Check the ratio against the thresholds: 4.5:1 for AA normal text, 3:1 for large text, 7:1 for AAA.
3. The live preview shows exactly how the pair reads.

Example

Dark teal #22332f on pale mint #e6f2ee → about 10.9:1 — clears AAA comfortably. Grey #999 on white gives 2.85:1 — fails even large-text AA; that's the classic 'elegant but unreadable' footer.

The formula

contrast ratio = (L(lighter) + 0.05) ÷ (L(darker) + 0.05), where L = relative luminance from sRGB

What the result means

The ratio expresses how much brighter the lighter color is than the darker one. AA (4.5:1) is the legal accessibility floor in most jurisdictions; AAA (7:1) is the comfort standard for long reading. Large text gets a break because bigger glyphs tolerate lower contrast.

Frequently asked questions

Why 4.5:1 and not 50%?

WCAG ratios are computed through perceived luminance, not simple brightness — green contributes far more than blue to how bright a color looks. The math mirrors human vision.

My brand colors fail — what now?

Keep the brand color for accents, and derive a darker text variant of it for copy. Most brands fix this with one 'ink' version of their hue.

Does contrast matter for buttons and icons?

Yes — interactive elements need 3:1 against their surroundings so users can find them; this tool's large-text check is the same threshold.

Is my data private?

Yes — everything is computed in your browser.

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Explore the island world

• Palette Atoll — the island where this tool lives.
• The Main Island — drive the boat, explore the whole world.
• The 90s Kids Island — where most of us started.

Privacy & data: this tool runs entirely in your browser — nothing you type is uploaded, saved or sent anywhere. · Disclaimer: color values are computed with standard formulas; final appearance always depends on the display and medium. · Privacy Policy · Disclaimer