Color Contrast Checker

Sample Heading

This is sample body text to demonstrate readability at this contrast level.

Small text appears like this

Contrast Ratio

21.00:1

Excellent

Text Color

Background

WCAG Compliance

AA Normal Text

≥ 4.5:1

AA Large Text

≥ 3:1

AAA Normal Text

≥ 7:1

AAA Large Text

≥ 4.5:1

How to Check Color Contrast

Enter Your Colors

Type or paste hex, RGB, or HSL values into the foreground and background fields. You can also use the color picker to select colors visually.
Review the Contrast Ratio

The tool instantly calculates the contrast ratio between your two colors and displays a numeric score. A higher ratio means better readability.
Check WCAG Compliance

See at a glance whether your color pair passes WCAG Level AA (4.5:1 for normal text, 3:1 for large text) and the stricter Level AAA (7:1 and 4.5:1). Each criterion shows a clear pass or fail badge.
Adjust and Refine

If your combination fails, tweak the foreground or background until you reach a passing ratio. Use the swap button to quickly test reversed colors, or try the suggested alternatives the tool provides.

Who Uses a Contrast Checker?

Web Designers & Front-End Developers

Verify that every text and background combination in a design system meets WCAG AA or AAA before shipping. Catching contrast issues during development avoids costly redesigns after an accessibility audit.

Product & UX Teams

Ensure buttons, labels, and notifications remain legible across light mode, dark mode, and high-contrast themes. A quick contrast check prevents usability complaints from reaching support.

Content Creators & Marketers

Check that promotional banners, social media graphics, and email templates are readable on any screen. Accessible color choices increase engagement because more people can comfortably read the message.

Compliance & QA Auditors

Run through a site's color palette against Section 508 and ADA requirements. This tool makes it fast to document pass/fail results and recommend fixes for an accessibility remediation plan.

Why check color contrast?

Good color contrast ensures text is readable for everyone, including people with visual impairments. WCAG guidelines define minimum contrast ratios for accessibility. Meeting these standards also improves usability for all users.

Color contrast is one of the most impactful yet frequently overlooked aspects of web accessibility. The WCAG contrast ratio measures how much a foreground color stands out from its background, expressed as a value between 1:1 (identical colors) and 21:1 (black on white). Meeting the recommended thresholds ensures that text, icons, and interactive elements remain legible for users with low vision, color blindness, or anyone viewing a screen in bright sunlight.

This online contrast checker calculates the ratio instantly as you type and tells you whether the combination passes WCAG Level AA, Level AAA, or both. Unlike server-based analyzers, all processing happens in your browser -- nothing is uploaded. If you need to convert a color value before testing, use the Color Converter. For building an entire accessible palette from scratch, the Color Palette Generator can create harmonious schemes that still meet contrast requirements.

Accessible design is not just good practice -- it is often a legal requirement. The ADA, Section 508, and the European Accessibility Act all reference WCAG standards. Running your colors through a contrast checker before launch helps you avoid compliance issues, improves your Lighthouse score, and makes your content available to the widest possible audience. Pair this tool with the Image Color Extractor to pull colors from existing assets, or try the Glassmorphism Generator and Box Shadow Generator to build modern UI effects that still maintain readable text layers.

How it compares

Many contrast checking tools exist, but most require you to install a browser extension or upload a screenshot. This online contrast checker works instantly in any browser with no installation and no account. It supports hex, RGB, and HSL input, provides real-time results as you type, and flags both AA and AAA compliance at once. Paid design suites such as Figma and Adobe XD include built-in contrast features, but they lock you into a specific workflow and price tier.

Compared to popular alternatives like WebAIM's contrast checker, this tool adds a live text preview, one-click color swap, and automatic suggestions when a combination fails. Because everything runs client-side, your color data never leaves your machine -- making it safe for proprietary brand palettes and confidential design systems.

Tips for Better Color Contrast

Start with a contrast ratio of at least 4.5:1 for body text and work up from there; higher ratios are always safer.
Avoid placing text over images or gradients without a semi-transparent overlay to guarantee a consistent ratio.
Test your color palette in both light and dark modes; a pair that passes on a white background may fail on dark gray.
Use your brand colors for accents and decoration, but fall back to high-contrast neutrals for critical text and form labels.
Remember that placeholder text inside inputs also needs adequate contrast -- WCAG applies to all visible text, not just paragraphs.
Your input stays in the browser and is never uploaded to FindUtils. The page itself is not request-free: like the rest of the site it loads advertising and analytics scripts.

Frequently Asked Questions

What is WCAG contrast ratio?

WCAG (Web Content Accessibility Guidelines) defines minimum contrast ratios for text readability. Level AA requires 4.5:1 for normal text and 3:1 for large text. Level AAA requires 7:1 and 4.5:1 respectively.

What counts as large text?

Large text is defined as 18pt (24px) or larger for regular weight, or 14pt (18.5px) or larger for bold text. Large text has lower contrast requirements because it's easier to read.

Why does accessibility matter?

About 15% of the world's population has some form of disability. Good contrast ensures your content is readable by people with visual impairments, color blindness, or those using screens in bright environments.

How do I fix low contrast?

To increase contrast, make the foreground darker or the background lighter (or vice versa). Our tool shows real-time updates as you adjust colors, making it easy to find accessible combinations.

Is AA or AAA compliance required?

WCAG Level AA is the standard requirement for most websites and is legally mandated in many countries. Level AAA is stricter and recommended for maximum accessibility, especially for government or healthcare sites.

What contrast ratio do I need for icons and UI components?

Non-text elements such as icons, input borders, and interactive components require a minimum contrast ratio of 3:1 against adjacent colors under WCAG 2.1 Success Criterion 1.4.11. This applies to focus indicators, form field outlines, and graphical objects that convey information.

Does color contrast affect SEO?

Yes. Search engines factor accessibility into page experience signals. Google's Lighthouse audit penalizes insufficient contrast, which can lower your overall performance score and indirectly hurt rankings. Fixing contrast issues improves both SEO and user engagement.

How do I test contrast for color-blind users?

Contrast ratio calculations are independent of color vision deficiency because they measure luminance, not hue. A ratio that passes WCAG standards will be legible for most color-blind users. However, you should also avoid relying on color alone to convey meaning; pair color cues with labels, patterns, or icons.

Can I check contrast for dark mode designs?

Absolutely. Enter your dark mode foreground and background colors into the checker. The same WCAG ratio thresholds apply regardless of whether you use a light or dark theme. Many designers find that pure white text on very dark backgrounds can cause eye strain, so aiming for a slightly muted foreground often works better.

What is the difference between WCAG 2.1 and WCAG 3.0 contrast models?

WCAG 2.1 uses the relative luminance formula to compute contrast ratios on a scale from 1:1 to 21:1. The upcoming WCAG 3.0 draft introduces APCA (Advanced Perceptual Contrast Algorithm), which accounts for font size, weight, and polarity to produce a more perceptually accurate score. This tool currently evaluates against WCAG 2.1 standards.

Run it from code

$ curl -X POST \
  api.findutils.com/api/tools/color-contrast/execute \
  -d '{"foreground":"#000","background":"#fff"}'

$ claude mcp add findutils \
  --transport http https://mcp.findutils.com/
# then call findutils:color_contrast

API reference Add to Claude