100% Free In-browser Instant minify

CSS Minifier Free Online

Remove comments, whitespace and redundant semicolons from CSS instantly. Paste your code or upload a .css file — all processing happens in your browser, your code never leaves your device.

Drop a .css file here or click to browse
Never uploaded · How it works
Related tools: Compress Image HTML to Image Photo Editor JS Minifier

How it works

Minify CSS in 3 steps

1

Paste or upload

Paste your CSS into the input box, or drop a .css file directly onto the upload zone.

2

Auto-minify

The minifier runs instantly as you type, stripping comments, whitespace, and redundant semicolons.

3

Copy or download

Copy the minified CSS to your clipboard or download it as a .min.css file.

FAQ

Frequently asked questions

CSS minification removes all characters that are not necessary for the browser to parse and apply the stylesheet. This includes comments (/* … */), whitespace, newlines, and the last semicolon before a closing brace. The resulting file is functionally identical but significantly smaller.

Typical results range from 20–60% size reduction, depending on how much whitespace and how many comments your original CSS contains. Combined with gzip compression on your web server, the bandwidth savings are even greater.

No. All minification runs entirely inside your browser using JavaScript. Your code is never sent to any server and never leaves your device. This makes the tool safe even for proprietary or confidential CSS.

No. CSS minification only removes characters that have no effect on how the browser interprets the stylesheet. All selectors, property names, and values are preserved exactly. Always test in a staging environment before deploying to production.

Yes. The minifier handles all standard CSS constructs including @media queries, @keyframes, @font-face, custom properties (--var), and calc() expressions. Comments inside any at-rule are also stripped safely.

Everything you need to know about CSS Minification

Every byte counts when it comes to web performance. CSS is one of the first resources a browser must download and parse before it can render your page. Minifying your CSS reduces that file size, helping pages load faster — especially on mobile connections.

Why minify CSS?

Minified CSS files are smaller, which means faster download times and lower bandwidth costs. Search engines like Google use page speed as a ranking signal, so faster-loading pages can help your SEO. Tools like Google Lighthouse and PageSpeed Insights recommend minifying CSS as a best practice.

What our CSS minifier removes

Our tool strips block comments (/* … */), leading and trailing whitespace from each line, newlines, spaces around CSS operators ({ } : ; , > ~ + selectors), and trailing semicolons before closing braces. The output is a single-line, fully valid stylesheet.

When to use minified CSS

Always use minified CSS in production. Keep the original, readable source in your version control system and serve the minified version to users. Many build tools (webpack, Vite, Parcel) can automate this in a build pipeline. This tool is great for quick one-off minification without a build system.

CSS minification vs. compression

Minification and compression are complementary. Minification removes redundant characters at the source level. Server-side compression (gzip or Brotli) then compresses the already-minified file further for transfer. Using both gives you the smallest possible CSS payload.