Free Resources / CSS/JS Minifier

CSS/JS Minifier

Minify CSS and JavaScript files instantly. Everything runs in your browser -- nothing is uploaded to any server.

100% Private Instant No Limits

Drag & drop CSS/JS files here

or click to browse. Accepts .css and .js files. Multiple files supported.

Minifying files...

Results

File Type Original Minified Saved
0
Files
0 KB
Original
0 KB
Minified
0%
Saved

How It Works

Upload or Paste

Drag and drop .css or .js files, or switch to Paste mode to minify code directly. Process multiple files at once.

Instant Minification

CSS is minified with csso and JavaScript with Terser -- the same engines used by major build tools. Results appear instantly.

Download Results

Download each file individually or grab all minified files as a single .zip archive. See exact size savings per file.

Frequently Asked Questions

Minification removes whitespace, comments, and shortens variable names in CSS and JavaScript without changing functionality. This reduces file size, which means faster page loads, lower bandwidth costs, and better Core Web Vitals scores -- all of which improve SEO and user experience.
No. This tool uses production-grade minifiers (csso for CSS, Terser for JS) that are designed to preserve functionality. However, it's always good practice to test minified output before deploying. If your JavaScript relies on function name reflection, enable the "keep names" option in your build pipeline.
No. All minification happens entirely in your browser. The csso and Terser libraries run locally via JavaScript. Your source code never leaves your device, making this tool safe for proprietary and sensitive codebases.
CSS minification removes whitespace, comments, and merges duplicate rules. JavaScript minification is more aggressive -- it also shortens variable names, removes dead code, and optimizes expressions. JS minification typically achieves higher compression ratios (30-60% vs 15-30% for CSS).