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Contrast checker
Compare text and background colors, calculate their contrast ratio, and quickly check the relevant WCAG AA and AAA thresholds.
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- Instant
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- Works offline
- Clipboard
Aa
Contrast ratio:
- AA normal text:
- AA large text:
- AAA normal text:
Why use this tool?
Measure the contrast ratio between text and background colours and compare the result with WCAG AA and AAA thresholds. The tool helps quickly assess a colour pair before using it in an interface, website, or component.
Smart processing
Create and verify web content with settings designed for usable results.
Supported formats
Web formats, metadata, and structured content depending on the available features.
Save time
Get a clean, ready-to-use result in seconds without installing software or configuring a complex workflow.
Guide
How to use this tool
- 1
Enter both colours
Provide the text colour and background colour you want to compare.
- 2
Check the contrast ratio
The tool calculates contrast and reports the corresponding WCAG levels.
- 3
Adjust colours if needed
Change either colour and test again until the result fits your intended use.
Tips and best practices
- Good contrast improves readability, but accessibility also depends on text size, visual hierarchy, and interaction design.
- Applicable thresholds can differ between normal text and large text.
- Review colours in their real context, including different screens and hover, focus, or disabled states.
Frequently asked questions
What is a contrast ratio?
It measures the luminance difference between two colours, from 1:1 for identical colours up to 21:1 for maximum contrast.
What is the difference between WCAG AA and AAA?
AAA uses stricter thresholds than AA. The appropriate target depends on the content and the level of conformance you want.
Does a good ratio guarantee accessibility?
No. Contrast is only one criterion among others such as keyboard access, labels, structure, and visible focus states.
Are the entered colours stored or uploaded?
No. The calculation runs locally in your browser.
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