CSS Minifier

Compress your CSS by removing spaces, line breaks and comments and shortening values, so your stylesheets load faster without changing how your site looks.

In your browserFree

Paste or type to begin. Everything runs in your browser.

How it works

How to use the CSS Minifier

  1. 01

    Paste CSS, drop a .css file onto the input, or load the sample.

  2. 02

    Comments, whitespace and redundant values are removed. Turn on restructuring to also merge duplicate rules.

  3. 03

    Check the size saving under the editor, then copy or download the minified CSS.

About this tool

Why minify CSS?

CSS is render-blocking: the browser won't paint the page until it has downloaded and parsed your stylesheets. Smaller CSS files download faster, which improves page load time, user experience and Core Web Vitals, and can contribute to better search rankings.

This minifier is powered by CSSO. It removes whitespace and comments, shortens colours (#ffffff becomes #fff), drops redundant units and zeros, and can optionally restructure your stylesheet by merging duplicate selectors and declarations for even bigger savings, all while keeping the CSS functionally identical.

  • Real optimisation

    Goes beyond removing spaces: shortens colours, numbers and shorthand values.

  • Optional restructuring

    Merge duplicate rules and declarations for extra savings.

  • Keep license comments

    Preserve /*! … */ comments that licenses require.

  • See the saving

    Before and after sizes and the percentage saved are shown instantly.

FAQ

Frequently asked questions

Is minified CSS safe to use in production?

Yes. Minification only removes characters that browsers ignore and rewrites values in equivalent shorter forms. Restructuring is also safe in most cases, but test the result if you rely heavily on rule order.

How much smaller will my CSS be?

Typically 15–40% before gzip, depending on how many comments and how much whitespace the original has.

Should I still gzip or Brotli my CSS?

Yes. Minification and server compression work together, and you'll get the smallest transfer size by using both.

Are my files uploaded anywhere?

No. This tool runs entirely in your browser using JavaScript. Your files and text never leave your device, so it's safe for private or confidential work.

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