Developer Tools
CSS Minifier
Minify CSS by removing whitespace and comments to reduce file size. It is designed for a browser-first paste-and-run workflow.
Free in browser No sign-up required Immediate results
How it works
Run this tool in three short steps.
01
Paste CSS
Paste or upload .css.
02
Auto-minify
Whitespace and comments removed.
03
Copy
Copy or download.
Questions
What people ask before they use this tool.
What does CSS minification do?
Removes whitespace, comments, and unnecessary characters from CSS to reduce file size.
Does it break my CSS?
No. Only safe removals: whitespace, comments, trailing semicolons. All rules are preserved.
How much reduction?
Typically 20-40% depending on formatting.
Is my code uploaded?
No. All processing in your browser.
Does it remove comments?
Yes. All CSS comments (/* */) are removed.
Does it merge duplicate rules?
No. It only removes whitespace and comments. Use a CSS optimizer for rule merging.
Can I upload .css files?
Yes.
Can I download?
Yes. Download as .css file.
Does it handle Sass/SCSS?
It processes the CSS syntax. Sass variables and nesting are preserved as-is.
Is there a size limit?
It works well for typical snippets and page-sized stylesheets in the browser. Very large files depend on your device memory and browser performance.
Does it work on mobile?
Yes.
Does it remove vendor prefixes?
No. All prefixes (-webkit-, -moz-, etc.) are preserved.
Can it beautify CSS?
This tool minifies. For formatting, use a CSS beautifier.
Can I start using it right away?
Yes. Paste CSS or upload a file and the minified version appears directly on the page. See all <a href="/developer-tools">Developer Tools</a>. Also try <a href="/json-formatter">JSON Formatter</a>.
What other tools?
HTML Minifier, JS Minifier, JSON Formatter, and <a href="/text-diff-checker">Diff Checker</a>, plus 20+ more.
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Minify CSS by removing whitespace and comments. Paste code or upload a stylesheet, review the output immediately, then copy or download it from the same browser-first workspace.