CSS Minifier
Compress CSS stylesheets by removing whitespace, comments, and redundant code to reduce file size — all in your browser with before/after size comparison.
Get notified the day we launch. No spam, ever.
What to expect
Built for developers
Minify CSS by removing whitespace, comments, and redundant declarations to reduce file size and improve page load speed.
Runs client-side. Your data never leaves your browser.
No ads, no trackers, no popups. Pure focus.
Paste code or upload files. Both modes supported.
Share output with teammates via a permanent link.
Adapts to your system preference automatically.
Fully responsive. Works on any screen size.
About this tool
OpenFormatter's CSS Minifier compresses CSS stylesheets online for free. Removes whitespace, comments, redundant semicolons, and shortens hex colors and font weights. Shows original vs minified file size and compression percentage. Supports CSS3 including media queries, keyframe animations, and custom properties. All processing happens in your browser — no data is sent to any server.