What does CSS minification do?
Minification strips everything a browser does not need to render your styles: comments, whitespace, line breaks, and the last semicolon in a block. The CSS still behaves identically, but the file is smaller, so it downloads and parses faster. This tool minifies for production and can also beautify minified CSS back into readable, indented code.
How much smaller does it get?
Savings vary with coding style, but minification commonly shrinks a stylesheet by 20% to 50% before any server compression is applied. On large stylesheets that is a meaningful reduction in page weight, and it compounds across every visitor, which is why every production build pipeline minifies CSS by default.
Minifying vs. compressing
These are two different, complementary steps. Minifying changes the source text itself by removing redundant characters. Compressing (gzip or Brotli) is applied by the web server on top, encoding the bytes more efficiently for transfer. You want both: minify first, then let the server compress the result for the largest total saving.
Can you un-minify CSS?
Yes. Minification is reversible in the sense that you can re-add indentation and line breaks to make the code readable again, which is exactly what the beautify mode does. What cannot be recovered are the original comments, since they were discarded. Keep your unminified source in version control and treat the minified file as a build artifact.
Last updated: July 2026