CSS Minifier
Free online CSS minifier. Instantly compress and optimize CSS code by removing whitespace, comments and unnecessary characters. Reduce file size for faster web performance.
What does CSS minification do?
CSS minification removes unnecessary whitespace, comments, line breaks, and optimizes CSS syntax to reduce file size without changing functionality. The visual appearance and behavior of your website remain exactly the same.
How much file size can I save with CSS minification?
Typically you can achieve 20-40% reduction in file size, depending on how much whitespace, indentation, and comments exist in your original CSS. Heavily commented or poorly formatted CSS can see even greater reductions.
Is my CSS code sent to a server?
No, all minification is performed locally in your browser using JavaScript. Your CSS code never leaves your device, ensuring complete privacy and security.
Will minification break my CSS?
No, the minifier only removes unnecessary characters and optimizes syntax. The CSS functionality remains identical. All selectors, properties, and values are preserved exactly as intended.
What is the difference between minification and compression?
Minification removes unnecessary characters from the code itself (whitespace, comments), while compression (like Gzip or Brotli) compresses the entire file at the binary level. Both techniques are complementary and should be used together for maximum file size reduction.
Can I minify CSS with preprocessors like Sass or Less?
Yes, you can minify the output CSS generated by preprocessors. Simply compile your Sass or Less files first, then paste the resulting CSS into the minifier for further optimization.
Should I minify CSS in production?
Yes, minifying CSS in production is a web performance best practice. It reduces file size, decreases page load time, and improves Core Web Vitals scores. Most modern build tools automatically minify CSS during the build process.
Does minification affect CSS debugging?
Minified CSS is harder to read and debug. For development, use unminified CSS with source maps. For production, use minified CSS to optimize performance. Many build tools can generate both versions automatically.
What CSS optimizations does this tool perform?
This tool removes whitespace, comments, and line breaks. It also optimizes certain CSS values and removes unnecessary characters while preserving all functionality and visual appearance.
Can I minify large CSS files?
Yes, this tool can handle CSS files of any size. The minification process is fast and efficient, working entirely in your browser without any file size limitations.
Is there a limit on how many times I can use this tool?
No, there are no usage limits. You can minify as many CSS files as you need, completely free, with no registration required.
Does this tool work offline?
Once the page is loaded, the minification process works entirely offline in your browser. You don't need an internet connection to minify your CSS files.
How to Use CSS Minifier
Compress CSS by stripping whitespace, comments and redundant characters. Minification runs locally in your browser, so your code never leaves your machine.
- Paste your stylesheet into the editor — anything from a snippet like body { color: red; } to a full file.
- Toggle Keep license comments (/*! ... */) if you need to preserve legal and license notices.
- Compare the size of the minified output with the original to see the savings.
- Copy the minified CSS and ship it instead of the readable version.
Leave license comments enabled when minifying third-party CSS — removing /*! ... */ blocks can violate the library's license terms.
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