CSS Minifier
Paste your CSS and get minified output instantly — removes comments, whitespace and newlines without affecting how your styles render. The tool runs entirely in your browser so nothing is ever uploaded to a server. Smaller CSS files mean faster page loads, better Core Web Vitals scores and improved user experience.
How to Use the CSS Minifier
Paste your stylesheet into the Input CSS box above and click Minify CSS. The minified version appears in the output box along with a size comparison showing original bytes, minified bytes and the percentage saved. Click Copy Minified CSS to copy the result to your clipboard, then paste it directly into your project or deployment pipeline.
What Does CSS Minification Remove?
This minifier performs the following transformations:
- CSS comments — everything between
/*and*/is stripped. - Unnecessary whitespace — leading and trailing spaces, tabs and multiple consecutive spaces are collapsed to a single space or removed entirely.
- Newlines and carriage returns — all line breaks are removed so the output is a single line.
- Spaces around punctuation — spaces around
:,;,{,}, and,are eliminated. - Trailing semicolons — the last semicolon before a closing brace is redundant and can be removed.
CSS Minification vs Gzip Compression
Minification and Gzip (or Brotli) compression are complementary techniques — you should use both. Minification removes redundant characters from the file itself, reducing its raw size by 20–40%. Gzip then compresses the resulting text further, often achieving 70–90% compression over the wire. Most web servers (Apache, Nginx, Caddy) can be configured to serve Gzip-compressed responses automatically. The two techniques stack, giving you the smallest possible transfer size.
When to Minify CSS
Always minify CSS before pushing to production. Avoid minifying source files you actively edit — instead, maintain a readable source version and generate the minified output as part of your build process. Tools like Vite, Webpack, Parcel and PostCSS all include CSS minification as a built-in feature, automating this step on every build. Use this online minifier for quick one-off tasks, snippets, or when you don't have a build pipeline set up.
Frequently Asked Questions
What is CSS minification?
CSS minification is the process of removing all unnecessary characters — comments, whitespace, newlines and redundant semicolons — from a stylesheet without changing how it renders. The result is a functionally identical but smaller file that loads faster.
Does minifying CSS break my styles?
No. Minification only removes characters the browser ignores anyway. Your page will look and behave exactly the same. Always verify in a staging environment before deploying minified CSS to production.
How much does CSS minification reduce file size?
Most CSS files shrink by 20–40% through minification alone. Combined with server-side Gzip or Brotli compression, total bandwidth savings often exceed 80% compared to the original uncompressed file.
Should I minify CSS in development?
No — keep your CSS readable during development so you can debug it easily. Only minify for production. Use a build tool like Vite, Webpack or PostCSS to automate minification so production always gets the optimised file.