Does minification change CSS behavior?

It should not, but invalid CSS or edge cases can still cause issues.

Should I keep original CSS?

Yes. Keep readable source files and use minified output for delivery.

Is minification enough for performance?

It helps, but unused CSS removal and caching also matter.

Developer tool

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CSS Minifier

Minify CSS by removing unnecessary whitespace.

CSSMinifierCode

Try CSS Minifier Now

Live

Status

Free

Access

Browser workflow

Mode

Live workspace

Use CSS Minifier online

Enter your input, generate the result, copy the output, or download a processed file when this tool supports export.

LiveBrowser workflowDeveloper

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Shared CSS Workspace

Minify CSS conservatively

Uses a standards-aware parser instead of regex replacement. Formatting uses Prettier's CSS parser and preserves comments. Minification removes structural whitespace without rewriting selectors or declaration values.

Browser only

CSS inputMaximum 0.95 MB

Drop one .css file here. CSS stays in this browser and is never executed.

Press Ctrl+Enter or Command+Enter to minify.

Upload CSS

Formatter indentationMinifier comments

Open CSS Formatter

Output

Minified CSS

No CSS output yet

Paste valid CSS, then choose Format or Minify. Parser errors will show a source location when available.

Paste CSS or upload a .css file to begin.

Privacy
CSS files and text are parsed in a browser worker. Input and output are not sent to TanzaiTools servers.

Compatibility
Parsing and formatting do not prove that every declaration works in every browser. Test output in your supported browser matrix.

Safe minification
The minifier avoids selector merging, declaration reordering, value shortening, prefix changes, and other aggressive optimization.

Recent local CSS outputs (0)

Successful outputs up to 146 KB are saved only in this browser.

Loading CSS workspace...

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Overview

About CSS Minifier

CSS Minifier reduces CSS text by removing unnecessary whitespace and comments for smaller snippets. It is useful for quick embeds, demos, email templates and simple optimization tasks. For production websites, use a build pipeline that can minify, prefix and bundle CSS safely.

Features