WCAG Contrast Checker

Free online wcag contrast checker — verifying text remains readable for low-vision users.

100% Private — Runs entirely in browserInstant calculation & resultFree, no sign-up

Text color (hex)Background color (hex)

The quick brown fox jumps over the lazy dog.

Large heading sample

Contrast ratio: 14.47:1

PASSAA — normal text (needs 4.5:1) — Body copy under 18pt

PASSAA — large text (needs 3:1) — 18pt+ or 14pt bold

PASSAAA — normal text (needs 7:1) — Enhanced accessibility

PASSAAA — large text (needs 4.5:1) — Enhanced, large type

PASSUI components (needs 3:1) — Borders, icons, focus rings

Why check color contrast with ToolJiffy WCAG Contrast Checker?

Color contrast between body text and background colors determines whether content is readable for users with low vision, color blindness, or age-related visual impairments. Meeting Web Content Accessibility Guidelines (WCAG 2.1 Level AA and AAA) is mandatory for government, educational, and commercial websites under ADA and European accessibility laws. ToolJiffy WCAG Contrast Checker calculates color contrast ratios instantly in your browser.

W3C Relative Luminance Contrast Engine: Calculates exact contrast ratios (1:1 to 21:1) using W3C sRGB formulas.
WCAG 2.1 AA & AAA Compliance Reports: Passes or fails Normal Text (4.5:1), Large Text (3:1), and UI Component standards.
Live Typography Contrast Preview: Renders sample headlines, body text, and button components on target background colors.
100% On-Device Browser Security: Calculates contrast ratios locally in browser memory without cloud tracking.

W3C sRGB Relative Luminance Math Engine

ToolJiffy's contrast checker transforms HEX color codes into linear sRGB values to calculate relative luminance ($L = 0.2126R + 0.7152G + 0.0722B$). It evaluates the contrast ratio formula ($(L1 + 0.05) / (L2 + 0.05)$) against WCAG AA and AAA thresholds.

Whether auditing brand color palettes, checking button hover state contrast, or designing accessible web UI components, instant contrast verification ensures legal compliance and readability.

Client-side security for private brand palettes

Testing contrast ratios for confidential client brand colors, unreleased UI designs, or design system palettes should never send color data to remote third-party servers.

ToolJiffy operates on a zero-cloud architecture. All contrast math runs 100% locally in your browser tab. Your color data never leaves your device.

Step-by-step guide to checking color contrast

Select text & background colors: Input text HEX color (e.g. #111827) and background HEX color (e.g. #ffffff).
Inspect contrast score: Review the calculated contrast ratio (e.g. 16.8:1) and WCAG AA/AAA pass indicators.
Preview typography sample: Inspect the live typography canvas to verify comfortable reading contrast across text sizes.

Frequently asked questions

How does the WCAG Contrast Checker work in browser memory?

ToolJiffy calculates color contrast ratios between text color and background color using the W3C sRGB relative luminance formula, reporting pass/fail scores for WCAG 2.1 Level AA and Level AAA standards.

What contrast ratios are required for WCAG 2.1 AA and AAA compliance?

Level AA requires a contrast ratio of at least 4.5:1 for normal text and 3:1 for large text (18pt+ or 14pt bold). Level AAA requires 7:1 for normal text and 4.5:1 for large text.

What is sRGB relative luminance in WCAG color contrast math?

Relative luminance calculates the relative brightness of any color point in the sRGB color space, normalized from 0 (darkest black) to 1 (brightest white).

Is my color combination or site brand data sent to any cloud server?

No, 100% private. All color conversions (HEX, RGB, HSL) and contrast ratio calculations execute locally inside your browser memory. Your data never leaves your device.

Can I pick colors directly using a visual color picker or HEX input?

Yes! Use visual color pickers or type HEX codes (`#ffffff`, `#000000`) for text and background colors.

What is non-text contrast requirement under WCAG 2.1 Level AA?

UI components (button borders, form input outlines, focus indicators, graphics) require a contrast ratio of at least 3:1 against adjacent colors.

Does ToolJiffy suggest accessible color fixes if my contrast fails?

Yes! The tool suggests closest accessible color adjustments to pass WCAG AA/AAA thresholds.

Is ToolJiffy WCAG Contrast Checker free without limits?

Yes! ToolJiffy is 100% free with unlimited usages, zero account sign-ups, and zero watermarks.

Explore related developer tools

Check accessibility with Accessibility Checker, generate palettes with Color Palette Generator, convert color codes with HEX RGB Converter, or pick colors with Color Picker.