13 / css-minifier
free online tool
CSS Minifier
Minify CSS by removing whitespace and comments to reduce file size.
Minified CSS will appear here...
how to use
- 01
Paste your CSS code into the input panel.
- 02
Click 'Minify' to remove whitespace, comments, and redundant characters.
- 03
Copy the minified CSS.
about
What is this tool?
CSS minification removes unnecessary characters from CSS source code — whitespace, comments, and redundant semicolons — without changing its functionality. Smaller CSS files load faster, reducing page load time and improving Core Web Vitals scores.
why use this tool
- -Reduce CSS file size by up to 30–50% for faster page loads.
- -Improve Lighthouse performance scores.
- -No build tools required — instant browser-based minification.
- -Your code never leaves your browser.
features
- -Removes comments and whitespace.
- -Preserves all CSS functionality.
- -Shows original vs minified size comparison.
- -One-click copy of minified output.
comparison
CSS Minification: Before vs After
| File Type | Typical Size | After Minification | Saving |
|---|---|---|---|
| Small site CSS | 15 KB | 9 KB | ~40% |
| Medium framework CSS | 80 KB | 52 KB | ~35% |
| Large utility CSS (Tailwind) | 350 KB | 18 KB (purged + minified) | ~95% |
| Single component | 2 KB | 1.2 KB | ~40% |
All processing happens entirely in your browser using JavaScript. No files, text, or data are ever sent to a server. Your data stays on your device.
✦ tip from dragontail
When I launched Dragontail's site, I minified CSS manually for the first few deploys using exactly this kind of tool. The habit taught me to write cleaner CSS from the start — fewer redundant rules, fewer comments that just repeat the property name. Now our build pipeline handles it automatically, but I still use a browser-based minifier for quick experiments and isolated file checks.
faq
Will minification break my CSS?
No. Minification only removes non-functional characters. The CSS remains fully valid and functional.
Should I minify CSS in development?
No. Keep readable CSS in development and minify as part of your production build process.
Is my code sent to a server?
No. All processing is done locally in your browser.