Free online CSS minifier and compressor. Reduce CSS file size by removing whitespace, comments, and optimizing shorthand properties. Minify stylesheets for faster page loads and better Lighthouse performance scores. Essential for frontend developers optimizing web performance. 100% browser-based.
100% browser-based — your data never leaves your device
Minify and compress CSS by removing whitespace, comments, and optimizing property values.
Copy your CSS code and paste it into the input textarea above.
Press Minify to compress your CSS by removing whitespace, comments, and optimizing property values.
Copy the minified CSS for production use. See the size savings displayed below.
Drop a file here or click to browse
Ctrl+Enter to minify
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This tool strips whitespace and comments from your CSS and optionally consolidates related declarations into shorthand, producing a smaller file that renders exactly the same.
Minified output is not meant for editing, but the CSS Formatter can restore it whenever you need to change something.
Stylesheets are often the largest text payload a page ships, so compression here has an outsized effect on load time and on metrics like Core Web Vitals. This tool prepares production-ready CSS: edit in readable expanded form, minify for the deployment, and ship the compressed version to users. The explicit byte and percentage savings let you track how much weight you removed on each build.
For mobile networks and slow connections the stakes are higher. A stylesheet that lost 30-50 percent of its size transfers faster, parses faster, and leaves more bandwidth for content. Even modest savings accumulate across many pages, which is why minification belongs in every performance workflow alongside removing unused rules before you compress.
Your production stylesheet is a snapshot of your design system and internal implementation. Uploading it to an online compressor creates a copy of that intellectual property on a service you do not control.
Local minification keeps the original and the compressed CSS on your device. Nothing is uploaded, so proprietary styling never reaches another server.
Copy your CSS code and paste it into the input textarea above.
Press Minify to compress your CSS by removing whitespace, comments, and optimizing property values.
Copy the minified CSS for production use. See the size savings displayed below.
Practical examples to help you get the most out of CSS Minifier:
Input:
.button {
background-color: #007bff;
color: #fff;
padding: 10px 20px;
border-radius: 4px;
}
Output: .button{background-color:#007bff;color:#fff;padding:10px 20px;border-radius:4px}Input: /* Primary button */ .btn-primary { background: blue; } /* end */
Output: .btn-primary{background:blue}Some CSS hacks rely on specific whitespace patterns or comments. Minification may strip these. Always test minified CSS in target browsers before deploying.
Shorthand optimization combines properties like margin-top, margin-right into margin. Verify the combined shorthand produces the correct visual result in all cases.
It removes whitespace, comments, and empty rulesets while optionally combining shorthand properties to reduce file size.
No. Minified CSS renders identically to the original — only unnecessary characters are removed.
Yes. Use the CSS Formatter to beautify and expand minified CSS when you need to edit it.
Typical savings are 30-50% for well-formatted CSS. Files with extensive comments or indentation see the largest reductions.
Removes unnecessary spaces, tabs, and newlines while preserving selector and property structure.
Removes CSS comments to reduce file size without affecting styles.
Combines related properties into shorthand notation where safe.
Shows original vs minified size with byte count and percentage saved.
CSS Minifier is useful in a variety of scenarios across different workflows:
Compressing CSS files for production deployment and faster load times
Reducing stylesheet size for better Core Web Vitals scores
Optimizing CSS delivery for mobile networks and slow connections
Use the CSS Minifier for production and the CSS Formatter for development. Switching between them lets you optimize for both readability and performance.
For best results, remove unused CSS rules before minifying. This gives much larger file size savings than minification alone.
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