DeveloperSpace
This CSS file intends to warn developers about possible risks and mistakes that exist in HTML code. It can also be used to roughly evaluate a site's quality by simply including it as an external stylesheet.
Identifies accessibility issues in your React.js elements
Automated accessibility tools audit
Ace by DAISY, an Accessibility Checker for EPUB
A script to test the heading outline of a document
CSS Accessibility Validator for your HTML
EIII accessibility testing bookmarklet
flagging accessibility concerns