Contrast Checker

Check color accessibility according to WCAG 2.1 guidelines.

100% local processing. Your data never leaves your computer
Sample TitleThis is a sample text to check contrast.Small sample text
Contrast ratio
15.99:1
AA Normal text>= 4.5:1
PASS
AA Large text>= 3:1
PASS
AAA Normal text>= 7:1
PASS
AAA Large text>= 4.5:1
PASS

About this tool

The Contrast Checker calculates the contrast ratio between a text color and a background color, showing whether the combination passes or fails the accessibility criteria from the WCAG 2.1 guidelines. This is essential for ensuring content is readable by people with low vision or color blindness.

To use it, enter or pick the foreground (text) color and the background color using the color pickers or by typing HEX values directly. The tool automatically calculates the contrast ratio and displays the result for each WCAG level: AA Normal (minimum 4.5:1), AA Large (minimum 3:1 for large text), AAA Normal (minimum 7:1), and AAA Large (minimum 4.5:1). A sample text preview shows visually how the combination looks in practice.

Front-end developers use this tool during theme implementation to verify that the colors chosen by the designer meet accessibility requirements before delivering code. Designers use it to validate color palettes during the creative process. Accessibility auditors check existing pages to identify issues to fix. Anyone responsible for public interfaces — including government systems and products with compliance requirements — needs to ensure at least Level AA conformance.

All calculations happen in your browser with no data sent to servers. No account is required.

Frequently asked questions

What is WCAG and why does it matter?

WCAG (Web Content Accessibility Guidelines) are the international accessibility standards for web content, maintained by the W3C. Meeting contrast criteria ensures text is readable by people with visual impairments and is a legal requirement in many countries.

What is the difference between AA and AAA levels?

AA is the minimum recommended level for most websites and requires a 4.5:1 ratio for normal text. AAA is the most stringent level (7:1) and is typically applied to high-impact text. Level A does not cover color contrast requirements.

Is this tool free?

Yes, completely free and no signup required.

Is my data sent to any server?

No. The contrast ratio calculation happens entirely in your browser. No color values or data are transmitted.

Does it work on mobile?

Yes. The interface is responsive and the color picker works on mobile devices.