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CSS Minifier

Minify CSS code by removing whitespace, comments, and unnecessary characters. Shows compression ratio.

What this tool does

This CSS Minifier compresses your CSS code by stripping out everything the browser does not need to read: comments, extra whitespace, newlines, and redundant characters. The result is a smaller file that loads faster on your website.

Paste any CSS stylesheet and get production-ready minified output in one click, along with a before-and-after size comparison showing exactly how many bytes you saved.

How minification works

CSS minification applies several transformations to reduce file size without changing how the browser interprets the styles:

  • Comment removal — Block comments (/* ... */) are stripped entirely
  • Whitespace collapse — Spaces, tabs, and newlines are removed or collapsed
  • Punctuation tightening — Spaces around {, \

Who should use this

  • Web developers preparing stylesheets for production deployment
  • Front-end engineers optimizing page load performance
  • Designers who hand-write CSS and want a quick way to compress it
  • Students learning about web performance and build tooling
  • Anyone pasting CSS into an email template, CMS, or inline style block where size matters

How to use

  1. Paste your CSS code into the input area
  2. Click the Minify button
  3. Review the minified output and size statistics
  4. Click Copy to copy the minified CSS to your clipboard
  5. Use the Clear button to start over with new CSS

Example

Before (readable CSS):

/* Main layout */
body {
  margin: 0px;
  padding: 0px;
  font-family: Arial, sans-serif;
}

.container {
  max-width: 1200px;
  margin: 0 auto;
}

After (minified CSS):

body{margin:0;padding:0;font-family:Arial,sans-serif}.container{max-width:1200px;margin:0 auto}

In this example, the file size drops from around 160 bytes to about 95 bytes, a savings of roughly 40%.

FAQs

Q: Does minification break my CSS?
A: No. Minification only removes characters that are not needed for the browser to interpret your styles correctly. The visual output is identical.
Q: Is my CSS sent to a server?
A: No. All processing happens locally in your browser. Nothing is uploaded or stored.
Q: Should I minify CSS before or after using a preprocessor like Sass?
A: After. Compile your Sass or Less to regular CSS first, then minify the compiled output.
Q: How does this compare to tools like cssnano or clean-css?
A: Build-tool minifiers like cssnano can apply more advanced optimizations such as merging duplicate selectors and shorthand property collapsing. This tool covers the most common and impactful optimizations for quick, one-off minification without a build pipeline.
Q: Can I use the minified output in production?
A: Yes. The output is valid CSS that is ready for production use.

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