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Swizztool

CSS Minifier

Compress CSS stylesheets client-side to improve web performance. Strips comments, collapses spacing, shortens 0px to 0, and shows how much smaller the file gets.

Your text 490 chars · 28 lines

Result 490 B → 352 B (28% smaller)

How to use CSS Minifier

  1. Paste your CSS.
  2. Choose which optimizations to apply.
  3. The minified CSS and the size saving update as you type.
  4. Copy or download the result.

About CSS Minifier

Minify CSS by removing comments and extra whitespace and shortening zero values, and see the size saving as you type. Spaces that CSS needs, such as inside calc(), are preserved so your styles keep working.

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What the minifier changes

Comments are removed, whitespace around braces, colons, semicolons, and commas is collapsed, and the last semicolon in each rule is dropped. Zero values with units, such as 0px and 0em, become 0.

Values that only look like zeros are left alone: 10px, 1.0px, and percentage keyframe selectors like 0% are not touched. Spaces around + and - in calc() are kept because CSS requires them.

What it does not do

It does not merge duplicate rules, reorder properties, or rewrite colors. Those optimizations can change how styles cascade, so they are best left to a build tool that understands your whole project.

Custom properties, media queries, and @keyframes pass through unchanged apart from whitespace.

Common uses

Small sites
Minify a hand-written stylesheet before uploading it.
Inline styles
Compact CSS before putting it in a <style> tag or email template.
Third-party embeds
Shrink CSS for widgets and snippets you distribute.
Checking savings
See how much of a stylesheet is comments and whitespace.

Questions about CSS Minifier

Does this CSS minifier handle CSS variables and media queries?
Yes, all modern CSS syntax including custom properties (--var), @media queries, and keyframes are safely preserved.
Is minified CSS harder to debug?
Yes. Keep the original for editing and only deploy the minified version.
Is my CSS uploaded?
No. Minifying happens in your browser.
Why is calc() not fully compressed?
CSS requires spaces around + and - inside calc(), so those spaces are kept on purpose.
How much smaller will my CSS get?
Typically 15 to 40 percent, depending on how many comments and how much indentation the original has.

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Comments

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