About this tool
Minifying CSS removes comments and unnecessary whitespace and applies safe optimizations, producing a smaller stylesheet that loads faster. The styling behaviour is preserved exactly.
Paste your CSS and see the minified output with a before/after size comparison. Powered by CSSO, it performs structural minification — merging and restructuring rules — on top of whitespace removal. Copy the result, or expand it again with the CSS beautifier.
Minification runs locally — your styles never leave your browser.
Frequently asked questions
Is the minified CSS equivalent to the original?
Yes — CSSO applies only safe transformations, so the computed styles are identical. It removes comments, whitespace and redundancy.
What optimizations does it apply?
Beyond stripping whitespace and comments, it merges adjacent rules, removes overridden declarations and shortens values where the result is provably equivalent.
How do I read the minified CSS?
Use the CSS beautifier to expand it back into a readable, indented form.