CSS Minifier
Minify or beautify CSS — reduce file size instantly
About CSS Minifier
CSS minification removes all unnecessary characters — whitespace, comments, newlines — without changing the functionality of the stylesheet. Smaller CSS files load faster, improving page speed and Core Web Vitals scores. This free CSS Minifier also includes a CSS Beautifier to format compressed or messy stylesheets into clean, readable code. Shows exact size reduction in bytes and percentage.
How to Use CSS Minifier
- 1Paste your CSS code into the input area, or click "Load Sample" to try an example.
- 2Choose "Minify" to compress (remove comments and whitespace) or "Beautify" to format.
- 3Click the action button — the output appears instantly with size reduction stats.
- 4Copy the minified CSS or use it directly in your project for faster page loads.
Common Use Cases
Minifying CSS typically reduces file size by 20–40%. For even better results, combine it with Gzip compression on your server — the two together can cut CSS delivery size by 80%+.
⭐ Popular Free Tools
Frequently Asked Questions
What does CSS minification remove?
CSS minification removes: all comments (/* ... */), whitespace and indentation used for readability, newlines between rules, redundant semicolons after the last property in a rule, unnecessary zero units (0px → 0), and color shorthand (e.g. #ffffff → #fff). It does not change any CSS functionality.
How much does CSS minification reduce file size?
Typical CSS files are reduced by 20–40% through minification alone. When combined with Gzip or Brotli compression on the server, total size reduction is typically 70–85%. A 100KB CSS file can easily become 15–20KB after both optimizations.
Can CSS minification break my website?
Standard minification should not break any valid CSS. However, some edge cases can cause issues: very old browser hacks that rely on specific whitespace, incorrect use of semicolons, or CSS that uses the important CSS Hacks (filter:expression). Always test your site after minifying.
Should I minify CSS manually or use a build tool?
For production websites, use an automated build tool like Vite, webpack or Parcel — they minify CSS automatically as part of the build process. Manual minification (like this tool) is useful for quick one-off optimizations, WordPress stylesheets, or third-party CSS you receive without source.