Documentation
Everything is short. Start with the basics, jump to the reference when you need it.
New here?
Add WhatTheCSS to Chrome, click the toolbar icon on any page, and start inspecting. Free, no account.
Getting started
Install on Chrome
Add WhatTheCSS from the Web Store, pin it, and run your first toggle.
Your first inspection
Hover, pin, edit a value, copy CSS. The whole loop in five minutes.
Reference
Keyboard shortcuts
A handful of shortcuts cover the entire feature surface. Printable.
Inspection modes
Default and Peek. What each view shows and when to use it.
Pinned tooltip & live editing
Pin to enter the four-tab editor. Click any value to change it.
Pro
Page audits
Palette, Fonts, Tokens. Audit a whole page in one click.
Export a component
Send a pinned component to CodePen, an HTML snippet, or clean Tailwind.
Component library
Save, search, rename, and re-export pinned components. All local.
License management
How activation works and what the three license tabs do.
Troubleshooting
Common issues
Common problems and how to fix each one.