Contrast Checker is a tool used to evaluate the visibility and legibility of text over a background color. It aims to ensure that the foreground text stands out clearly against the background, making it readable for most users, including those with visual impairments such as color blindness or low vision.
There are several key factors that tool measures:
- Color Contrast Ratio: This is a numerical value that represents the contrast between the foreground (text) and the background. The Web Content Accessibility Guidelines (WCAG) suggest a minimum contrast ratio of 4.5:1 for normal text and 3:1 for large text. For enhanced accessibility, higher ratios are recommended.
- WCAG Compliance Levels: The tool may check against different levels of WCAG standards, such as Level AA or Level AAA. The higher the level, the more stringent the requirements for contrast and readability.
- Text Size and Weight: Some contrast checkers allow you to input the size and weight (boldness) of text, as these factors also affect readability.
- Pass/Fail Indicators: The tool may provide a simple pass or fail assessment based on the color combination's adherence to established guidelines.
To use a contrast checker, you typically enter the hex codes, RGB values, or other color values for your text and background colors. The tool then calculates the contrast ratio and provides feedback on accessibility compliance.
You can find contrast checkers as standalone online tools, as features within design software, or as browser extensions that help designers and developers create content that is accessible to a wider audience.