Performance

CSS Minifier

Paste your CSS to minify it (strip comments, collapse whitespace, tighten punctuation) — or switch to Unminify to beautify minified CSS back into readable, indented code.

We strip comments and collapse whitespace to shrink your file.

What is a CSS minifier?

A CSS minifier removes comments, collapses whitespace and tightens punctuation so your stylesheet is smaller — usually 20–40% smaller — with no change to how it renders. This css minifier online is instant and free.

Minify or unminify CSS

Use Minify to shrink CSS for production, or Unminify to unminify css — turning css minify to normal, readable code with one declaration per line. The built-in css beautifier is handy for reading or editing compressed stylesheets.

Why CSS minification matters

Smaller CSS downloads and parses faster, improving page speed and Core Web Vitals. It's one of the easiest performance wins and safe to apply to any stylesheet.

How to use the CSS minifier

  1. Pick Minify or Unminify.
  2. Paste your CSS.
  3. Click the button and copy the result.

More performance tools

Pair this with our JS Minifier, HTML Minifier, Page Speed Test and the full free SEO tools suite.

Frequently asked questions

A CSS minifier removes comments, collapses whitespace and tightens punctuation so your stylesheet is smaller and downloads faster — usually 20–40% smaller — with zero runtime impact. Paste your CSS and get a production-ready version instantly.
Switch to the Unminify tab, paste your minified CSS, and run it. We re-indent the rules and put each declaration on its own line so the CSS is readable again — a 'css minify to normal' / CSS beautifier built into the same tool.
No. It only removes comments and whitespace and tightens safe punctuation, so the rendered styles are identical. It's a safe, instant optimization.
Smaller CSS files download and parse faster, improving page speed and Core Web Vitals. Minifying your stylesheets is one of the easiest performance wins.
Completely free and online, with no account required. Both minify and unminify are included. It's part of WebsiteAuditTools' free suite of performance tools.