JS Minifier - Minify JavaScript Code Online Free

How to Use the JS Minifier

1. Paste your JavaScript — paste your JS code into the input area
2. Click Minify — the tool instantly compresses your code
3. Review the comparison — see original vs minified size and savings percentage
4. Copy the result — use the minified JS in your project
5. Verify it works — test the minified script to ensure no syntax issues were introduced

Minifying JavaScript removes whitespace, comments, and line breaks to reduce file size. Smaller scripts load faster and improve page performance. All processing happens in your browser — nothing is uploaded.

Features

• Whitespace removal — strips spaces, tabs, and newlines
• Comment stripping — removes // and /* */ comments
• Before/after comparison — see exact character and byte savings
• Reduction percentage — track your compression ratio
• One-click copy — copy minified output instantly
• Local processing — your code never leaves your browser

Use Cases

• Production deployment: Minify scripts before deploying to production for faster page loads
• WordPress optimization: Minify theme and plugin JavaScript to improve Core Web Vitals scores
• Build pipeline: Integrate minification into your build process (Gulp, Webpack, Vite)
• CDN uploads: Minify before uploading to CDN to reduce bandwidth costs
• Email scripts: Some email clients limit total code size — minifying helps stay within limits

FAQ

Does minification change my code’s behavior?

No. Minification only removes whitespace, comments, and newlines. It does not rename variables or change logic. Your code will behave identically, just in a more compact form.

How much can I save by minifying?

Typical JavaScript files compress 30-50%. Libraries like jQuery (normally ~90KB) minify to around 30KB. Larger files with heavy commenting can see 60%+ savings.

Should I use minified or unminified for development?

Always use unminified code during development for readable error messages and debugging. Only serve minified code in production. Many build tools handle this switch automatically.

Can I reverse minification (beautify the code)?

Partially. You can reformat the code with proper indentation, but original variable names, comments, and formatting are permanently lost. Always keep your original source files.

Is JS minification the same as uglification?

Uglification is a more aggressive form that also shortens variable names and function names. Simple minification only removes whitespace and comments. For production, uglification saves more bytes but makes code completely unreadable.

Tips

• Always keep your original, well-commented source files — minified code is for production only
• Combine multiple JS files into one before minifying to reduce HTTP requests
• Use source maps during development so you can debug minified production code