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CSS Minifier

Compress CSS by removing whitespace and combining rules where safe.

How to Use

  1. Paste your CSS code.
  2. Click Minify.
  3. Copy the compressed CSS.
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Frequently Asked Questions

Can I restore the original CSS?

No, minification is lossy in terms of readability. Keep your original file.

CSS Minifier Guide: Cut Stylesheet Bloat and Improve Render Speed

Large CSS files block rendering and delay interactivity. A CSS minifier removes unnecessary characters and sometimes consolidates rules to deliver faster, smoother page loads.

CSS is render-blocking by default, which means the browser cannot paint the page until every stylesheet is downloaded and parsed. A CSS minifier reduces that payload so users see content sooner, and search engines reward the improved speed.

What Is a CSS Minifier?

A CSS minifier removes whitespace, comments, and unnecessary semicolons. Some tools also merge duplicate rules, optimize shorthand properties, and strip outdated vendor prefixes. The output is a single continuous line of CSS that browsers interpret identically to the original.

Use Cases

  • Design systems – Shrink component libraries shipped to dozens of microsites.
  • Mobile-first projects – Reduce bytes over slow networks.
  • Third-party theme imports – Clean up bloated CSS from page builders.
  • Email development – Stay within client-specific size caps for inline styles.

How to Use Our CSS Minifier

  1. Paste your stylesheet into the input editor.
  2. Select safe mode for conservative changes or advanced mode for maximum compression.
  3. Review the diff to see exactly what was removed or rewritten.
  4. Download the minified file or copy it into your build pipeline.
  5. Generate a source map if you plan to debug in production.

Tips for Maximum Impact

  • Run minification as the final build step, after Sass, Less, or PostCSS processing.
  • Keep source maps so you can map production styles back to original lines.
  • Pair minification with HTTP/2 push or preloading for critical CSS paths.
  • Do not minify CSS intended for human editing; version control the original.

Ready to try it?

Use our free CSS Minifier now. No signup required.

Related Tools

  • HTML Minifier — Remove unnecessary whitespace and comments from HTML to reduce file size.
  • JS Minifier — Minify JavaScript to reduce load times and bandwidth usage.

External Resources