JavaScript Minifier – Minify & Beautify JS Online

A JavaScript minifier removes unnecessary characters from JS code — whitespace, comments, and newlines — and shortens variable names (mangling) to produce smaller, functionally identical code. This reduces file size and speeds up page load.

Yes. Minified JavaScript is syntactically identical to the original — only whitespace, comments, and optionally variable names are changed. Browsers execute minified JS exactly the same way as the original.

Minifying removes whitespace and comments. Uglifying additionally mangles variable names (e.g., "calculateTotal" becomes "a") for maximum compression. Terser does both when you use the Minify button.

Beautifying (also called formatting or pretty-printing) takes compressed or poorly formatted JS and adds consistent indentation, newlines, and spacing to make it readable. It is the reverse of minification.

No. This tool uses the Terser library entirely in your browser. Your JavaScript code is never sent to any server. All minification and beautification runs locally.

This tool uses Terser, the industry-standard JavaScript compressor used by Webpack, Vite, and most modern build tools. It supports ES2020+ syntax.

Typical savings are 30–60% depending on how much whitespace, comments, and long variable names the original code has. Combining minification with Gzip compression (which servers do automatically) can achieve 70–90% size reduction.

No. Terser only accepts JavaScript. You need to compile TypeScript to JavaScript first (using tsc or your build tool), then minify the resulting JS. TypeScript source with type annotations will cause a syntax error.