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CSS Minifier

Compress CSS stylesheets for production — strip whitespace, shorten color codes, remove comments, and see the exact bytes saved.

Remove whitespace Shorten colors Strip comments Merge selectors Size reduction % Copy output
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Free · No credit card · 50 credits/day

What minification removes

⬜

Whitespace

Removes spaces, tabs, and newlines between selectors, properties and values — the biggest single saving in most stylesheets.

💬

Comments

Strips /* block comments */ that document your CSS. Keep them in source; strip them in production.

🎨

Long color values

Shortens #ffffff → #fff and rgb(0,0,0) → #000. Saves bytes on color-heavy stylesheets.

0️⃣

Unnecessary zeros

Removes leading zeros (0.5rem → .5rem) and trailing zeros in decimal values.

🔁

Duplicate rules

Merges identical selectors that appear in multiple places — safe when order does not matter.

📦

Redundant units

Drops the unit from zero values (0px → 0) where CSS allows it, per spec.

Frequently asked questions

How much can CSS minification reduce file size?

Minification alone typically reduces CSS file size by 20–40%. Combined with Gzip or Brotli compression on the server, CSS files commonly reach 5–10% of their original size. For large stylesheets (100KB+), this can save hundreds of milliseconds of load time on mobile connections.

What is the difference between CSS minification and CSS compression?

Minification removes human-readable extras (whitespace, comments, long color names) at the CSS level. Compression (Gzip/Brotli) is applied by the server at the transport level. Both should be used together — they are complementary, not alternatives.

Should I minify CSS during development or only in production?

Minify only for production. In development, readable CSS with comments makes debugging much easier. Use a build tool (Vite, webpack, Parcel) with a minification plugin that runs automatically during your production build.

Does CSS minification change how styles are applied?

No. Minification is semantically lossless — it removes redundant whitespace and normalises values without changing how any rule is applied. The browser renders minified and non-minified CSS identically.

Related dev tools

Minify the rest of your front-end assets too.

JavaScript Minifier

Compress JavaScript files — remove whitespace, mangle variable names, strip comments.

 HTML Formatter

Beautify and indent HTML code, or minify it for production.

 Diff Checker

Compare your original and minified CSS to verify nothing changed semantically.

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