CSS Minifier & Beautifier Online
Minify CSS to reduce file size or beautify compressed CSS for readability. Free online CSS formatter.
What is CSS Minification?
CSS minification removes unnecessary whitespace, comments, and formatting from CSS code to reduce file size. Smaller CSS files load faster, improving website performance and Core Web Vitals scores.
When to beautify CSS?
Beautifying (formatting) CSS adds proper indentation and line breaks, making the code easier to read and maintain. Use it when debugging or reviewing minified stylesheets.
About This Tool
The CSS Minifier compresses your CSS by removing comments, whitespace, and redundant formatting to reduce file size for production deployment. Smaller CSS files load faster, improve Core Web Vitals scores, and reduce bandwidth costs for high-traffic websites.
Key Features
- Comment Removal — Strips all CSS comments (/* ... */) that are useful during development but waste bytes in production stylesheets.
- Whitespace Compression — Removes unnecessary spaces, tabs, and newlines while preserving the CSS rule structure to produce the most compact valid output.
- Beautify / Restore — Prettifies minified CSS back to a readable, indented format for editing or debugging compressed stylesheets.
- Browser-Based Processing — All CSS processing runs locally in your browser. Your code never leaves your device.
- Free & No Signup — Use this tool as many times as you need without creating an account or paying anything.
Common Use Cases
- Minifying production CSS files before deploying a website to improve page load speed and Lighthouse scores
- Compressing Tailwind CSS purged output or Bootstrap customizations for CDN delivery
- Reducing CSS bundle size in Next.js or Vite projects that do not auto-minify in all environments
- Decompressing and reading minified third-party stylesheets to understand or debug their rules
- Optimizing inline <style> blocks in HTML email templates to reduce email size
How to Use
Paste your CSS into the input panel on the left. Click Minify to compress the stylesheet or Beautify to format a minified stylesheet into readable code. The output appears on the right. Use the Copy button to copy the result to your clipboard.
Frequently Asked Questions
How much does CSS minification reduce file size?
Typically 20–40% for handwritten CSS with comments and formatting. Stylesheets with many comments or excessive whitespace can see reductions of 50% or more. Results vary based on your original code style.
Does minifying CSS change how it works?
No. Minification only removes characters that are invisible to the browser's CSS parser (comments and extra whitespace). The visual output of your web page is identical before and after minification.
Should I minify CSS manually or use a build tool?
Build tools like Vite, webpack, or Next.js automatically minify CSS in production builds. Use this manual tool for one-off files, third-party code snippets, or projects without a build pipeline.
Does CSS minification affect vendor prefixes?
No. This tool removes only whitespace and comments. Vendor prefixes like -webkit- or -moz- are preserved as-is. Advanced optimizers (like PostCSS with autoprefixer) handle prefix management separately.
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