100% client-side, nothing ever leaves your browser
Minify CSS
Paste CSS and get a smaller, minified stylesheet — comments and unnecessary whitespace removed, valid CSS behavior preserved.
How CSS minification works
A CSS-aware minification library parses your stylesheet into an AST and rebuilds it as compactly as possible — entirely inside your browser.
Paste your CSS
Paste a stylesheet of any size, including comments and formatted indentation.
Automatic minification
Comments and whitespace are removed, and some redundant structures are simplified where safe.
Copy or download
Review the byte savings, then copy the minified CSS or download it as a file.
Privacy note: minification runs entirely in your browser using a JavaScript library loaded from a CDN. Your CSS is never uploaded, logged, or stored on a server.
Common uses
Reducing stylesheet size
Smaller CSS files download and parse faster, improving page load times.
Preparing production builds
Minify hand-written or generated CSS before deploying it to a live site.
Embedding critical CSS
Compact inline critical CSS to keep the size of an inlined <style> block down.
Cleaning up pasted styles
Strip stray comments and formatting from CSS copied out of another tool or design export.
Frequently asked questions
Will minifying change how my CSS behaves?
No. This tool uses CSSO, a CSS-aware minification and structural optimization library that parses your stylesheet properly, so the visual result of the minified CSS matches the original.
Are comments removed?
Yes, ordinary comments are stripped since they have no effect on rendering. Comments marked as important, using a /*! ... */ syntax, are preserved by default.
Does this restructure or merge selectors?
The minifier can merge some redundant rules and simplify values where it's safe to do so, in addition to removing whitespace, which typically results in a smaller file than whitespace removal alone.
Is my CSS uploaded anywhere?
No. Minification runs entirely in your browser using a JavaScript library loaded from a CDN. Your CSS is never sent to a server.
What if my CSS has a syntax error?
The minifier will show an error describing what it couldn't parse. Fix the reported issue in your CSS and the tool will re-minify automatically.
How much smaller will my file be?
It depends on your original formatting and comment density. Heavily commented, indented stylesheets typically shrink the most; already-compact CSS will see a smaller reduction.
More tools
Additional utilities from the same toolkit. Curious what minification actually removes? Read the CSS Minification Guide →, or see the measured benchmark →