- W3C Markup Validation Service
- WAVE Web Accessibility Evaluation Tool
- axe - Web Accessibility Testing Chrome extension
- GreenIT-Analysis - Web Accessibility Testing (Chrome extension)
- Color Contrast Accessibility Validator
- NoCoffee vision simulator (Firefox)
- axe Accessibility Linter | Deque
- Assistant RGAA | Chrome | French
- Assistant RGAA | Firefox | French
- Siteimprove | Dutch | Requires email | Stores user data
- Tenon.io | Limited free service | Stores user data
Colour contrastNot everyone has perfect eyesight, especially in poor light. Poor contrast can be tested, together with other accessibility issues, using the web accessibility evaluation tool, WAVE, or by inspecting an element using browser tools.
A summary of WAVE's of the WCAG (Web Content Accessibility Guidelines):
- WCAG Level AAA
- A contrast ratio of at least 7:1 for normal text and 4.5:1 for large text.
- WCAG 2.0 level AA
- A contrast ratio of at least 4.5:1 for normal text and 3:1 for large text.
- WCAG 2.1
- A contrast ratio of at least 3:1 for graphics and user interface components.
Last updated: Fri Mar 19 2021