Minify CSS for production. Fast, secure, and completely free. All processing happens in your browser — no data is sent to any server.
A CSS Minifier removes comments and collapses all non-essential whitespace from a stylesheet — the space after a colon, the newline between rules, the indentation before a property — leaving a functionally identical but much smaller file. Browsers don't care whether a stylesheet is spread across a thousand readable lines or crammed into one; minifying is purely about reducing the number of bytes the browser has to download and parse, which matters most for render-blocking CSS loaded before the page can paint anything.
CSS is typically render-blocking: the browser won't paint the page until it has downloaded and parsed your stylesheet, so shaving kilobytes off that file directly improves how fast a page feels to a real visitor, especially on mobile networks. Minifying by hand is tedious and error-prone (a missing semicolon can silently break a rule); doing it automatically guarantees the output is both smaller and correct.
No, minification only removes whitespace and comments that have no visual effect; every selector and declaration keeps its original meaning and specificity.
No, this tool focuses on whitespace removal, not structural optimization. Use a dedicated CSS purging tool if you need to eliminate unused rules from a large codebase.
Yes, though it's harder to read. Most production setups pair minified CSS with a source map so DevTools can map it back to the original formatted source.
It reduces the uncompressed size, and while compression algorithms already handle repeated whitespace well, minifying still reduces parse time and payload size in edge cases without compression.
Yes, CSS custom properties (--my-color: #000) are fully supported and minified along with standard declarations.