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CSS Minifier — Minify CSS Online, Free

Minify CSS files online for free. Paste or upload your CSS and get compressed output instantly. Server-side processing — your CSS never runs in the browser. No signup required.

Processed on our server — your CSS is never stored or logged.
CSS Input 0 chars
Upload .css file

Server-side processing — your CSS never runs in the browser. Handles files up to 500 KB.

Need to format or validate CSS? Try the CSS Formatter + Validator →

Frequently asked questions

Does the CSS Minifier process files server-side?

Yes. All processing runs on our server via PHP. Your CSS is never parsed client-side, and files up to 500 KB are supported.

Does CSS minification change how the page looks?

No. Minification removes characters that have no effect on rendering: whitespace, comments, and redundant syntax. The browser interprets minified and formatted CSS identically.

What does the CSS Minifier do to my code?

It strips whitespace and comments, collapses shorthand properties (e.g. margin: 0 0 0 0 → margin: 0), and shortens six-digit hex colors to three digits where possible (#ffffff → #fff). The output is the smallest valid CSS string functionally identical to the input.

What is the maximum file size?

The maximum input size is 500 KB, which covers the vast majority of stylesheets. If you need to process larger files, split them into smaller chunks.

Is my CSS stored or logged?

No. Your CSS is sent over HTTPS, processed on the server, and the result is returned immediately. Nothing is written to disk or retained between requests.

How much can I expect the file size to shrink?

Typical reduction is 20–50% depending on how much whitespace, comments, and redundant shorthand your original file contains. The output panel shows the input size, output size, and percentage reduction.

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