Visually detect any potentially invalid or inaccessible HTML markup*

DiagnostiCSS highlights the following problems within markup:

Use it in your project

Good news everyone! DiagnostiCSS proudly supports Rails and any other Rack-compatible framework.

Use it everywhere

Just drag the DiagnostiCSS link to your bookmarks toolbar to apply it on any page.

Chrome Extension

Yep. This is it. Just install it.