Is Color Contrast Checker free to use?

Yes. Color Contrast Checker is available on the free plan with 20 daily runs. Paid plans add higher quotas for repeat work.

What contrast ratio do I need to pass WCAG?

4.5:1 for normal body text at level AA and 7:1 for AAA. Large text, roughly 18pt or 14pt bold, has a lower bar of 3:1 at AA.

Why do two colours that look clearly different to me fail the check?

Contrast is computed from relative luminance, a weighted measure that treats green as far brighter than blue. A red-on-green pairing can look distinct and still score badly, and perceived contrast drops further with age or low vision.

Does a passing ratio mean the text is actually readable?

It is a minimum, not a guarantee. Thin fonts, low-resolution screens, glare and motion all reduce legibility even at a compliant ratio, so size and spacing still matter.

What about text sitting over a photo or gradient?

Check the worst-case pixel behind the text rather than an average. A light patch under a light glyph can drop contrast far below the ratio you tested, so use a scrim or solid overlay when the background varies.

Color Contrast Checker Online

WCAG-Kontrastverhältnis zwischen Vorder- und Hintergrundfarben prüfen.

What this Developer tool does

WCAG-Kontrastverhältnis zwischen Vorder- und Hintergrundfarben prüfen. It helps developers format, validate, encode, decode, inspect, generate, or debug small pieces of technical data.

Color Contrast Checker helps with developer work directly in the browser. Use it for fast formatting, encoding, decoding, hashing, validation, and debugging tasks.

How to use Color Contrast Checker

Open the live tool at /tools/color-contrast-checker.
Paste the relevant code, token, JSON, CSV, URL, color, cron expression, regex pattern, or technical text into the input field.
Run Color Contrast Checker and check the generated result before using it in production work.

Best use cases for Color Contrast Checker

Debug API responses, configuration snippets, tokens, and structured data.
Prepare clean output for documentation, tickets, tests, or code review.
Avoid opening heavy desktop tools for quick developer checks.

Examples and checks for Color Contrast Checker

Example inputs

Body text colour against a page background
A button label against its fill colour
Placeholder or disabled text you are unsure about

Common mistakes to avoid

Checking the normal-text ratio while actually using large text
Testing against an average of a gradient or photograph
Ignoring hover, focus and disabled states

Output checklist

Record the ratio alongside the colour pair
Check every state the user will actually see
Re-test after any change to the palette

Colour pairs are not sensitive data, though a client palette under NDA is worth keeping off third-party services.

Color Contrast Checker inputs

Paste the relevant code, token, JSON, CSV, URL, color, cron expression, regex pattern, or technical text into the input field.

Color Contrast Checker output

The result is formatted, validated, decoded, encoded, generated, or explained output ready to copy into a development workflow.

Review before publishing

Do not paste production secrets, private keys, or sensitive credentials into any online utility unless you understand the risk.

Free usage limits and upgrades

The current free plan allows 20 daily runs. Pro allows 500 daily runs, and Business allows 3000 daily runs for heavier repeat work.

Color Contrast Checker input workspace
Color Contrast Checker result preview
Copy or download ready output
Free daily runs with paid upgrade limits

Compare Free, Pro, and Business plans for higher daily limits, larger uploads, longer file history, and repeat workflows.

Frequently asked questions

Is Color Contrast Checker free to use?: Yes. Color Contrast Checker is available on the free plan with 20 daily runs. Paid plans add higher quotas for repeat work.
What contrast ratio do I need to pass WCAG?: 4.5:1 for normal body text at level AA and 7:1 for AAA. Large text, roughly 18pt or 14pt bold, has a lower bar of 3:1 at AA.
Why do two colours that look clearly different to me fail the check?: Contrast is computed from relative luminance, a weighted measure that treats green as far brighter than blue. A red-on-green pairing can look distinct and still score badly, and perceived contrast drops further with age or low vision.
Does a passing ratio mean the text is actually readable?: It is a minimum, not a guarantee. Thin fonts, low-resolution screens, glare and motion all reduce legibility even at a compliant ratio, so size and spacing still matter.
What about text sitting over a photo or gradient?: Check the worst-case pixel behind the text rather than an average. A light patch under a light glyph can drop contrast far below the ratio you tested, so use a scrim or solid overlay when the background varies.

Related tools

Color Converter - Convert HEX and RGB colors into HEX, RGB, and HSL values.
Image Color Picker - Extract dominant HEX and RGB colors from an uploaded image.
ARIA Label Audit - Audit HTML snippets for missing accessible labels on common elements.
JSON Formatter - Format, validate, and minify JSON.
Base64 Encoder - Encode text or data snippets into Base64.
Base64 Decoder - Decode Base64 strings into readable text.

Browse more online tools