Check whether a text and background color pair is readable enough to meet accessibility standards. The Web Content Accessibility Guidelines define a contrast ratio between two colors, and set minimum thresholds so that people with low vision can still read your content. This checker computes the exact ratio using the official relative-luminance formula and tells you at a glance whether the pair passes AA and AAA for both normal and large text. A live preview shows real sample text in your chosen colors so you can judge it by eye as well as by number. Adjust either color until you clear the level you need. It runs entirely in your browser, instantly and privately.