Guide
WCAG Contrast Ratio Basics (Without the Jargon)
Learn what contrast ratios mean and how to apply AA/AAA targets in practical UI work.
Contrast ratio numbers can feel abstract at first. This guide explains what they mean in plain language and how to use them when reviewing text colors.
What a contrast ratio represents
It compares how different a text color is from its background.
Higher ratios generally mean easier reading.
AA and AAA in simple terms
AA is the common practical baseline for most web interfaces.
AAA is stricter and useful where maximum readability is needed.
Normal text vs large text
Large text can pass at lower ratios than normal body text.
Always classify text size correctly before deciding pass/fail.
How to apply this in a workflow
Check planned color pairs before development.
Retest final UI states after implementation.
When to read this
- Starting accessibility reviews.
- Training designers and developers.
- Creating color QA checklists.
Use ratios as a decision tool
You do not need to memorize every rule. Use a checker and know which threshold applies to your text size.