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CSS Minifier

Free CSS minifier. Compress CSS by stripping comments, whitespace, and unnecessary separators, with a reported size saving in bytes and percent.

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CSS

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Paste your CSS above.

Deep dive guides

A LITTLE CONTEXT · 3 MIN READWhat a CSS Minifier Actually Deletes

All 5 related guides

rem vs em vs px: CSS Units Explained — How px, em and rem really differ, the em compounding trap, the 62.5% root trick, and a decision rule for sizing text, spacing and borders.
Why Code Is Minified (and When Not To) — Minification explained: what gets deleted, which whitespace is load-bearing, per-language differences, and when to keep the readable version.
CSS Grid: Tracks, fr Units, and Gaps — How grid-template-columns and rows define the skeleton: track sizes, the fr unit, repeat(), minmax(), and gap.
What a CSS Minifier Actually Deletes — The four deletion passes behind CSS minification — comments, whitespace, punctuation spacing, final semicolons — with a worked example and what stays untouched.
Minifying HTML Without Breaking It — Why safe HTML minification is a classification problem: collapsing whitespace between tags while preserving pre, textarea, script and style — with a real example.

How css minifier works

CSS minification shrinks a stylesheet by removing everything the browser does not need: comments, redundant whitespace, and the spaces around braces, colons, semicolons, and commas. The minified file is functionally identical but smaller, so it downloads and parses faster.

This minifier removes /* ... */ comments, collapses all runs of whitespace to a single space, strips spaces around CSS punctuation, and drops the trailing semicolon before a closing brace. It reports the original size, the minified size, and the saving in bytes and as a percentage.

Paste your CSS and click Minify. The tool is a fast, safe transform that preserves selectors, properties, values, and at-rules. For production you may also want a full optimizer that rewrites shorthand and merges rules, but for most stylesheets this minifier captures the bulk of the saving.

Frequently asked questions

What does minification remove?

Comments, redundant whitespace, and spaces around braces, colons, semicolons, and commas, plus trailing semicolons before a closing brace. The CSS rules themselves are unchanged.

Will minification break my CSS?

No. The transform preserves selectors, properties, and values. The minified file is functionally identical to the original — only the human-readable formatting is removed.

How much size can I save?

It depends on how verbose the original CSS is, but 30 to 50 percent is typical for hand-written stylesheets with comments and indentation. The tool reports the exact saving.

Is this enough for production?

For most sites yes. If you want further savings, a full optimizer can merge duplicate rules and rewrite properties into shorthand, but that risks changing behaviour and is best left to a dedicated build tool.

CSS Minifier

Deep dive guides

How css minifier works

Frequently asked questions

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