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Compress and minify your CSS instantly with this free online tool. Removes comments, extra whitespace, and unnecessary characters to reduce file size — all without leaving your browser.
On this page
- How to Use This CSS Minifier
- Why Minify CSS?
- What This Minifier Does
- Privacy
- Recommended Reading
- More Free Developer Tools
- Frequently Asked Questions
- What is CSS minification and why does it matter?
- Is it safe to minify CSS for production websites?
- How much file size reduction can I expect from CSS minification?
- What is the difference between CSS minification and CSS compression?
- References
How to Use This CSS Minifier#
- Paste your CSS code in the input area
- Click Minify CSS to compress
- See size savings instantly
- Copy the minified output for your project
Why Minify CSS?#
- Faster load times — smaller files download quicker, improving Core Web Vitals
- Less bandwidth — save on hosting and CDN costs
- Better SEO — Google considers page speed as a ranking factor
- Production-ready — keep readable source, deploy minified
What This Minifier Does#
- Removes all CSS comments (
/* ... */) - Collapses whitespace and line breaks
- Removes unnecessary spaces around selectors and properties
- Strips trailing semicolons before closing braces
Privacy#
This CSS minifier runs 100% in your browser. Your CSS code is never uploaded to any server. Safe for proprietary stylesheets.
Recommended Reading#
Level up your CSS skills:
- CSS: The Definitive Guide — essential reading for mastering CSS
- Every Layout: Relearn CSS Layout — essential reading for modern CSS
- Web Performance in Action — essential reading for optimizing web assets
More Free Developer Tools#
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- Free URL Encoder & Decoder Online
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Frequently Asked Questions#
What is CSS minification and why does it matter?#
CSS minification removes whitespace, comments, and unnecessary characters from your stylesheets to reduce file size. Smaller CSS files load faster, improving page speed scores and user experience, especially on mobile connections.
Is it safe to minify CSS for production websites?#
Yes, minification is a standard production optimization used by virtually all major websites. It only removes formatting and comments — it does not change how your styles render. Always keep your original unminified source files for development.
How much file size reduction can I expect from CSS minification?#
Typical CSS minification reduces file size by 15–30%, depending on how much whitespace and comments your original files contain. Combined with gzip compression on your server, total transfer size can drop by 70–80%.
What is the difference between CSS minification and CSS compression?#
Minification rewrites the CSS file to remove unnecessary characters, producing a smaller file on disk. Compression (like gzip or Brotli) is applied by the web server during transfer. They complement each other — minify first, then serve compressed.
References#
- MDN — CSS Documentation — Thorough CSS reference and guides
- web.dev — Minify CSS — Google’s guide to CSS minification for performance
- Chrome DevTools — Unminified CSS Audit — How Lighthouse flags unminified CSS
- W3C — CSS Standards — Official CSS specifications and working drafts