Test a foreground and background pair, get the contrast ratio instantly, and see whether it meets WCAG AA or AAA for normal and large text.
How to use this Color Contrast Checker effectively?
Pick a foreground text color and a background color using the color inputs or quick presets. The live preview shows how text will appear on the chosen background, while the contrast ratio updates instantly. Check the AA/AAA badges for normal text and large text; large text has lower requirements, so headings may pass even if body text does not. If a combination fails, tweak the brightness or saturation until the ratio meets your target level. Use the swap button to quickly test inverted color schemes for dark or light themes. Once the ratio passes, copy the hex values into your CSS or design system and continue validating other UI states like hover or disabled text.
Why use an online contrast checker?
Accessibility requirements are easy to miss during visual design, especially when colors look good on a designer's screen but fail for users with low vision or color blindness. An online checker provides fast, objective feedback without installing plugins. It works in any browser, so you can verify colors during design reviews or while writing CSS. Because the calculation runs locally, you can test private brand palettes without uploading them. Using a contrast checker early reduces rework later and helps you build inclusive interfaces that meet WCAG guidelines.
Features breakdown
- Instant WCAG AA/AAA pass/fail badges for normal and large text.
- Live preview of text on your chosen background.
- Preset color pairs to speed up common checks.
- One-click swap for light and dark mode testing.
- Clear ratio display for documentation and audits.
- Local, in-browser calculations with no uploads.
Interpreting WCAG levels and making fixes
WCAG defines contrast ratios of 4.5:1 for normal text and 3:1 for large text at the AA level, while AAA requires 7:1 and 4.5:1 respectively. If your colors fail, adjust lightness first: darken the text or lighten the background to increase the ratio. Avoid relying on color alone to communicate meaning; pair colors with icons or labels. Check contrast in real UI states such as hover, focus, disabled, and error states because those often use lighter tones. When you cannot reach AAA without hurting the brand palette, aim for AA on body text and use larger sizes for headings.
A practical workflow for contrast testing
Start with your primary text and background colors and confirm AA compliance for body text. Next, test secondary text, placeholders, and disabled states since they usually have lower contrast. For buttons and links, check the default, hover, and active states; subtle hover colors often fail even if the default passes. If you use gradients or images, test the worst-contrast area or add a semi-transparent overlay. Finally, review the UI on multiple devices and brightness levels to confirm readability in real contexts. Keeping a small contrast checklist like this helps teams catch issues before a full accessibility audit.
FAQ
Q: What counts as large text in WCAG?
A: Large text is 18pt (24px) or larger for regular weight, or 14pt (about 18.5px) or larger for bold text. Large text can use lower contrast ratios.
Q: Do images or gradients affect contrast checks?
A: Yes. If text appears over images or gradients, contrast varies across the background. Test the worst-case areas or add a solid overlay to ensure readable text.
Q: Does the tool save my color pairs?
A: No. All calculations run in your browser and nothing is uploaded or stored.