The Ultimate CSS extension helps you write cleaner, more efficient styles by identifying:
- ❌ Duplicate class definitions — Flags class names that are defined multiple times across your stylesheets.
⚠️ Unused CSS classes — Warns you about CSS classes that are defined but not used anywhere.⚠️ Undefined class usage — Highlights any class used in your HTML/JS/JSX/TS/TSX files that isn’t defined in your CSS.
⚠️ Note: SCSS support is coming soon! This version focuses on stable and accurate diagnostics for standard CSS files.
Customize how Ultimate CSS analyzes your project by toggling a few helpful settings in the VSCode Settings UI:
- ✅ Analyze templates (HTML/JS/TS/JSX/TSX) – Detects undefined classes in your markup files
- ✅ Analyze duplicate CSS classes – Flags class names that are defined multiple times across stylesheets
- ✅ Analyze unused CSS classes – Warns you about styles that are defined but not used anywhere
You’ll find these options under “Ultimate CSS” in your VSCode Settings panel.
- Underlines issues directly in your code:
- Red for duplicate class definitions
- Yellow for unused or undefined class usage
- Scans your entire workspace — not just open files
- Keeps diagnostics up-to-date as you code
- Quick fixes for removing unused classes
- Suggestions for renaming or merging duplicates
- Install Ultimate CSS from the VSCode Marketplace.
- Open a project with CSS and HTML/JS/TS/JSX/TSX files.
- Start coding — the extension will automatically highlight issues across your styles.
| Command | Description |
|---|---|
Ultimate CSS: Run Diagnostics |
Manually triggers a full scan of your workspace |
- Reintroduce full SCSS support (with safer parsing)
- Add quick fixes for unused/duplicate classes
- Improve performance for large monorepos
- Configurable ignore rules or
.ultimatecssrc
This extension is licensed under the MIT License.
Have a feature suggestion or bug to report? Visit the GitHub Repo and open an issue. Your feedback helps make this better!