CSS minifier

Minify CSS for a leaner production file

CSS minification removes formatting that browsers do not need, such as comments and extra whitespace. It can reduce transfer size for production assets while leaving the stylesheet rules and declarations functionally equivalent.

When this tool helps

  • Create a compact copy of a finished stylesheet for deployment.
  • Compare source and minified sizes during a performance review.
  • Prepare small CSS snippets for embedding in a constrained template.

How to get a reliable result

  1. Save the readable source file in version control before minifying.
  2. Paste valid CSS and run the minifier once.
  3. Test the minified output on representative pages and screen sizes.

Practical example

A formatted rule such as body { color: black; } can be reduced to body{color:#000} when equivalent transformations are supported.

Important note

Minification is not validation. Existing syntax errors, unsupported nesting, or broken URLs can remain, so run visual and automated tests before replacing a production asset.