Accessibility Tools

Color Contrast Contrast check

Instantly detects the contrast between foreground and background colors according to the WCAG 2.1 standard. Make sure your design meets AA/AAA accessibility guidelines.

Foreground color (text color)
HEX
RGB
HSL
background color
HEX
RGB
HSL
Quick color selection
Instant preview

This is the preview title

This is an example preview of general text content. WCAG 2.1 recommends a contrast ratio of at least 4.5:1 for general text and a contrast ratio of at least 3:1 for large text (18pt and above or 14pt bold and above).

T
card title
Card description text example
Contrast Ratio
prospects / background
7.23 : 1
WCAG Rating
AA
WCAG 2.1 Conformity Assessment
AA general text Pass
Requires ≥ 4.5 : 1
AAA general text Pass
Required ≥ 7.0 : 1
AA large text Pass
Requires ≥ 3.0 : 1
AAA large text Pass
Requires ≥ 4.5 : 1
Accessibility improvement suggestions
The current color palette complies with WCAG specifications and requires no improvements.
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What is Color Contrast Checker?

Color Contrast Checker It is a free online tool designed for web designers, front-end developers and accessibility experts. It can quickly calculate the contrast between two colors and calculate the WCAG 2.1(Web Content Accessibility Guidelines) standards evaluate compliance with AA and AAA accessibility specifications.

What is WCAG contrast?

WCAG 2.1 defines the calculation method of color contrast, using the relative brightness (Relative Luminance) formula to calculate the contrast ratio between the foreground color and the background color. The higher the contrast, the easier the text is to read, especially for users with weak vision.

Why is contrast important?

Good color contrast not only improves the reading experience for all users, it is also a key element of accessible web design. With approximately 217 million people worldwide living with moderate to severe visual impairment, ensuring adequate contrast can make your website more inclusive while also avoiding potential legal risks.

How to use this tool?

The usage is very simple: set them separately on the leftForeground color (text color) withbackground color, you can adjust colors via the color picker or by directly entering HEX, RGB, or HSL values. A live preview, contrast value, and WCAG evaluation results are immediately displayed on the right. If the color matching does not pass the standard, we will also provide specific suggestions for improvement.

How contrast is calculated

Contrast is calculated according to the relative brightness formula of the WCAG 2.1 specification:L = 0.2126 × R + 0.7152 × G + 0.0722 × B, where R, G, and B are Gamma-corrected sRGB values. Contrast Ratio = (L₁ + 0.05) / (L₂ + 0.05), where L₁ is the lighter color and L₂ is the darker color.

Frequently Asked Questions (FAQ)

What is WCAG?
WCAG (Web Content Accessibility Guidelines) is a web content accessibility guide developed by the W3C, which provides a series of recommended standards to make web content more accessible to people with disabilities. The current mainstream version is WCAG 2.1, which covers contrast, navigation, semantics and other aspects.
What is the difference between AA and AAA?
AA is the basic accessibility standard, and most countries and organizations have legal requirements (such as ADA, Section 508) to achieve at least AA level. AAA is a more advanced accessibility standard that requires a stricter contrast ratio threshold (general text ≥ 7:1). Not all websites can achieve AAA throughout the entire website, but they should work towards this goal as much as possible.
What is "large text"?
According to WCAG definition, large text refers to text that is "18pt (approximately 24px) or larger" or "14pt (approximately 18.67px) bold or larger". Since large text has a larger area and lower reading threshold, the contrast ratio requirement is relatively loose (AA only needs ≥ 3:1).
Does this tool support Color Blind simulation?
The current version of Color Contrast Checker focuses on contrast calculation and WCAG evaluation. Future updates will consider adding a color blindness simulation function to help designers create color schemes that are friendly to all users.
How to improve color contrast?
If the contrast is insufficient, it is recommended to: ① darken the color of the text (such as changing from light gray to dark gray or black); ② brighten the background color (such as changing from dark to light color); ③ increase the font weight (bold) or font-size (font-size) of the text; ④ avoid using overly complex gradients or patterns on the background. The tool's improvement suggestions area provides specific suggestions based on your color palette.
Is higher contrast better?
Generally speaking, higher contrast ratios do improve readability, but too high contrast ratios (such as pure black #000 and pure white #FFF, contrast ratio 21:1) may cause eye fatigue when reading for a long time. A contrast ratio between 7:1 and 15:1 is the most comfortable range for most content.
Will this tool save my data?
Not at all! All color calculations are done in your browser, and none of your action data is sent to any server. This tool does not require an internet connection to work (except when loading assets for the first time), and you can use it completely offline.

Browser compatibility

This tool uses standard Web API (HTML5, CSS3, ES6+) and supports all modern browsers:

🌐
Chrome
Latest version
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Firefox
Latest version
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Safari
Latest version
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Edge
Latest version

Privacy Statement

This tool executes entirely in your browser. Any colors you enter are not sent to any server. We do not use cookies or tracking with this tool.