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JS Minifier & Beautifier

Minify JavaScript to reduce file size or beautify JS for readability. Free online JavaScript minifier using Terser with size comparison.

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What is JS Minifier & Beautifier?

JavaScript minification removes whitespace, comments, and shortens variable names where safe, reducing file size by 30-60%. This improves page load times and reduces bandwidth costs. Beautification reformats compressed JavaScript for debugging and code review.

How to Use

  1. Paste your JavaScript code in the input area
  2. Click Minify to compress or Beautify to format
  3. Minification uses Terser — the same engine used by Webpack and Vite
  4. See the size savings for minified output
  5. Download the result as a .js file

Examples

Minify JS

Inputfunction greet(name) { const msg = 'Hello, ' + name; console.log(msg); return msg; }
Outputfunction greet(n){const o="Hello, "+n;return console.log(o),o}

Beautify JS

Inputconst f=n=>n*2;console.log(f(21));
Outputconst f = n => n * 2; console.log(f(21));

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Frequently Asked Questions

Is minified JavaScript harder to debug?

Yes. For debugging, use source maps or keep the original unminified code. In production, minified JS is standard practice. Modern browsers support source maps that map minified code back to the original.

What minifier engine does this use?

Terser — the industry-standard JavaScript minifier used by Webpack, Vite, Rollup, and other bundlers. It performs dead code elimination, variable mangling, and property optimization.

Does minification break JavaScript?

Very rarely. Terser is highly reliable and widely tested. However, code that relies on Function.prototype.toString() or specific variable names in error messages may behave differently after minification.