Contrast Ratio

The contrast ratio measures the difference in brightness between text and its background, ensuring that content is legible for users with visual impairments. A high contrast ratio improves readability, particularly for users with low vision or color blindness, and is essential for meeting accessibility standards like WCAG (Web Content Accessibility Guidelines).

Low contrast text is one of the most common — and most avoidable — accessibility failures in SaaS products. It's also a sign of a design that looks good in a Figma mockup on a calibrated monitor but becomes unreadable on a laptop screen in a bright room. WCAG requires a 4.5:1 ratio for normal text, and checking this takes seconds with any color contrast tool.

Apple's Human Interface Guidelines require a minimum 4.5:1 contrast ratio for all text in iOS apps — apps that fail this check are flagged during App Store review, and fixing contrast issues is one of the most common accessibility rejections developers receive.