Free CSS Minifier
Compress & optimise your CSS instantly — remove whitespace, comments & redundant code.
How It Works
Paste or Upload
Paste CSS directly or upload a .css file from your computer.
Choose Options
Toggle which optimisations to apply — comments, whitespace, colours and more.
Instant Minification
Processing happens in milliseconds — no waiting, no queues.
Copy or Download
Copy to clipboard or download the minified .css file instantly.
Secure & Private
Your code is never stored. Processing is done in memory and discarded immediately.
100% Free
No account, no limits, no watermarks — free forever.
Why Minify Your CSS?
Every kilobyte of CSS your browser downloads delays the moment your page becomes usable. Minifying CSS strips out the bytes a browser doesn't need — whitespace, indentation, comments and redundant semicolons — so the stylesheet downloads and parses faster. On a real site this directly improves your Core Web Vitals (especially First Contentful Paint and Largest Contentful Paint), which Google uses as a ranking signal. Smaller CSS also means lower bandwidth bills and a snappier experience on slow mobile connections.
CSS Minification vs. Gzip Compression
These two work together, not against each other. Minification rewrites your CSS to be smaller before it's sent. Gzip/Brotli compression then squeezes that already-smaller file even further during transfer. Minifying first gives compression less repetitive text to work with, so the combination beats either technique alone. Best practice: minify at build time, then let your server (or a CDN like Cloudflare) apply Gzip/Brotli on top.
What Exactly Gets Removed
- Whitespace & line breaks — spaces, tabs and newlines browsers ignore.
- Comments —
/* ... */notes meant for developers, not browsers. - Trailing semicolons — the last
;in a rule block is optional. - Redundant units & zeros —
0pxbecomes0,0.5becomes.5.
Nothing that changes how your page looks is ever touched — the output is functionally identical to your original CSS.
Best Practices for Minified CSS
- Keep an unminified source file for editing — only minify the version you ship.
- Serve minified CSS with a long cache header so returning visitors don't re-download it.
- Combine minification with critical CSS inlining for the fastest first paint.
- Re-minify whenever you change your styles — never edit a minified file by hand.
Who Uses a CSS Minifier?
Web developers shrink stylesheets before deploying to production. Students & beginners learn how clean, compact CSS is delivered in the real world. Bloggers and site owners on WordPress, Shopify or custom sites paste their theme CSS here to speed up page loads without a build tool. Agencies use it as a quick check before handing a site to a client. If your CSS ships to a browser, minifying it is a free, instant performance win.