Compress CSS
Paste or upload CSS code to minify and compress. Remove whitespace, comments, and optimize for production.
Original Size
0 KB
Compressed Size
0 KB
Reduction
0%
100% Secure
All processing happens in your browser. Your files never leave your device.
Super Fast
Process multiple files in seconds with our optimized browser-based tools.
High Quality
Keep your files clear and usable while reducing size or converting formats.
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Learn more about this tool
About CSS Compression
CSS minification removes unnecessary spaces, comments, and formatting so stylesheets are smaller and faster to deliver. This helps frontend performance, deployment workflows, and bandwidth usage. The tool runs locally in your browser, which is useful when you are working with private code or client projects. Whether you are preparing bilingual English and French documents, submitting files to CRA and Service Canada, or collaborating cross-border with US teams, this tool keeps your files lean and aligned with Canadian privacy expectations — nothing leaves your device.
How to Minify CSS Online
Paste your CSS code
Copy your stylesheet into the input panel.
Choose a minification level
Select the level that matches your workflow, from basic whitespace removal to stronger optimization.
Minify and copy output
Generate the compact CSS in your browser, then copy the result into your production build or deployment pipeline.
Frequently Asked Questions
How does CSS minification work?
CSS minification removes unnecessary characters like whitespace, comments, line breaks, and redundant semicolons. The resulting CSS is functionally identical but much smaller, leading to faster downloads.
Will minified CSS work the same?
Yes, minified CSS is functionally identical to the original. Only non-essential characters are removed — all selectors, properties, and values remain intact.
What compression level should I use?
For most cases, the recommended level provides the best balance of size reduction and safety. Use advanced for maximum compression when you can test the output thoroughly.
Is this CSS minifier free?
Yes, completely free with no limits. Process as many CSS files as you need, no registration required.
Does this CSS minifier upload my code to a server?
No. All processing happens locally in your browser using JavaScript, so your stylesheet never leaves your device. This makes it safe for private or client code. Because nothing is uploaded, there are no transfer limits — even multi-megabyte files minify in under a second.
How much smaller will my CSS file be after minification?
Most stylesheets shrink 20 to 40 per cent from removing whitespace, line breaks, and comments. A 100 KB file typically drops to 60-80 KB minified, and to 15-25 KB when the server also applies gzip or Brotli compression.
Should I keep the original unminified CSS file?
Yes, always. Keep a readable source file such as style.css in your repository and deploy the minified copy as style.min.css. Minified output is one long line, which is nearly impossible to edit, so change the original and re-minify after every update.
Can I minify CSS with media queries and animations?
Yes. Minification only strips whitespace and comments, so media queries, custom properties, keyframe animations, imports, and vendor prefixes all remain fully functional. Just make sure your input is valid CSS first — malformed rules may produce unexpected output in any minifier.
When to Minify CSS
Page Speed
Reduce CSS file size to improve page load times and Core Web Vitals scores
Production Deploy
Prepare CSS files for production deployment with optimized output
Bandwidth Saving
Reduce bandwidth costs by serving smaller CSS files to users
SEO Optimization
Faster loading pages improve search engine rankings and user experience
Why Choose Let Compress?
References & Resources
Authoritative specifications and references for the file formats this tool works with.