Text color
Background color
Contrast
8.42
- Pass
Small text
WCAG AA
- Pass
Large text
WCAG AA
- Pass
Small text
WCAG AAA
- Pass
Large text
WCAG AAA
Color Blindness Simulation
Info:
Small text: below 18pt. Large text: 18pt+ or bold 14pt+.
Light background
Quote n. 26
I do not know whether things will get better if we change; what I do know is that they must change if they are to get better.
Georg Christoph Lichtenberg
Dark background
Quote n. 26
I do not know whether things will get better if we change; what I do know is that they must change if they are to get better.
Georg Christoph Lichtenberg
Small text
Large text
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History of Contrast Ratio
Understanding WCAG and accessibility standards
WCAG Standards
The Web Content Accessibility Guidelines (WCAG) were developed by the World Wide Web Consortium (W3C) to make web content more accessible to people with disabilities. The contrast ratio requirements were introduced to ensure text is readable for users with visual impairments.
Development
WCAG 1.0 was published in 1999, establishing the first contrast ratio requirements. WCAG 2.0 (2008) refined these standards with more precise formulas. WCAG 2.1 (2018) added additional success criteria. The current contrast ratio formula was developed based on research into human visual perception and color science.
Why It Matters
Proper contrast ratios ensure that text is readable for everyone, including users with color blindness, low vision, or those viewing content in bright sunlight. This makes the web more inclusive and accessible to millions of users worldwide.
The Formula
The contrast ratio is calculated using the relative luminance of colors. It ranges from 1:1 (no contrast) to 21:1 (maximum contrast, like black on white). WCAG AA requires 4.5:1 for normal text and 3:1 for large text. WCAG AAA requires 7:1 for normal text and 4.5:1 for large text.