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Free CSS Minifier & Beautifier Online

Compress CSS to shrink file size for production, or beautify minified CSS back into readable, indented code. Runs entirely in your browser.

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  • Runs in your browser
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Guide

What does CSS minification do?

Minification strips everything a browser does not need to render your styles: comments, whitespace, line breaks, and the last semicolon in a block. The CSS still behaves identically, but the file is smaller, so it downloads and parses faster. This tool minifies for production and can also beautify minified CSS back into readable, indented code.

How much smaller does it get?

Savings vary with coding style, but minification commonly shrinks a stylesheet by 20% to 50% before any server compression is applied. On large stylesheets that is a meaningful reduction in page weight, and it compounds across every visitor, which is why every production build pipeline minifies CSS by default.

Minifying vs. compressing

These are two different, complementary steps. Minifying changes the source text itself by removing redundant characters. Compressing (gzip or Brotli) is applied by the web server on top, encoding the bytes more efficiently for transfer. You want both: minify first, then let the server compress the result for the largest total saving.

Can you un-minify CSS?

Yes. Minification is reversible in the sense that you can re-add indentation and line breaks to make the code readable again, which is exactly what the beautify mode does. What cannot be recovered are the original comments, since they were discarded. Keep your unminified source in version control and treat the minified file as a build artifact.

Last updated: July 2026

Frequently Asked Questions

What does CSS minification do?
CSS minification removes all unnecessary characters from CSS code - whitespace, line breaks, and comments - without changing functionality. This reduces file size, which improves page load speed.
How much can CSS minification reduce file size?
Typical reduction is 20–60% depending on how much whitespace and comments the original code contains. Well-formatted source code with extensive comments sees larger reductions.
Should I minify CSS for production?
Yes. Minifying CSS for production reduces bandwidth usage and improves page load times, which benefits both user experience and SEO (Core Web Vitals). Keep beautified source files for development.
What is the difference between minifying and compressing?
Minification removes unnecessary characters from the code itself. Compression (like gzip or Brotli) is applied at the server/transport level on top of minified files. Use both together for maximum file size reduction.
Can I un-minify CSS?
Yes, use the Beautify mode to add back readable formatting and indentation to minified CSS. This won’t restore original comments or variable names if they were removed, but it makes the structure readable again.