Contrast ratio measures the difference in luminance between text and its background. A higher ratio improves readability, especially for users with low vision or color blindness. WCAG 2.1 requires at least 4.5:1 for normal text (AA) and 7:1 for enhanced contrast (AAA).

This demo performs a simulated scan using typical contrast patterns. For a true pixel-perfect audit of your own site, we recommend our Chrome Extension, which captures rendered colors exactly as users see them, or use our API for automated bulk checking.

AA is the minimum requirement for most web accessibility laws (e.g., Section 508). AAA is the enhanced level with stricter contrast rules: 7:1 for normal text and 4.5:1 for large text (vs. AA's 4.5:1 and 3:1). AAA compliance is harder but provides better readability.

The simulation checks a representative set of text nodes (paragraphs, headings, buttons, links). In a full live audit, every visible text element is analyzed, including those inside iframes or dynamically loaded content (via the extension).

Adjust either the text color or background color to meet the required ratio. Use our integrated color picker or consult our contrast ratio calculator for exact adjustments. Often darkening the text or lightening the background solves most problems.