JavaScript Minifier

Compress and minify JavaScript by removing whitespace, comments, and unnecessary characters. Shows exact byte savings so you know the impact. Preserves /*! licence comments and is safe for production use.

Paste your JavaScript above and click Minify JS to see the result.

About the JavaScript Minifier

This free online JavaScript minifier compresses JS files by removing whitespace, newlines, and comments — reducing file size without changing how the code executes. Smaller JS files mean faster downloads and improved page load performance.

Features

Removes all whitespace, indentation, and blank lines
Strips single-line (//) and block (/* */) comments
Preserves /*! licence and attribution comments
ASI-safe — correctly handles JavaScript's automatic semicolon insertion rules
Correctly handles string literals, template literals, and regex patterns
Shows exact byte savings (original → minified with % reduction)
Downloads with .min.js extension
100% client-side — your code never leaves your browser

How to use

Paste your JavaScript into the input box (or click Sample to load an example).
Click Minify JS.
The stats bar shows the original size, minified size, and percentage saved.
Copy the result or download it as a .min.js file.

How minification works

Whitespace removal — spaces, tabs, and newlines between tokens are removed where safe.
Comment stripping — all // line and /* block */ comments are removed. Licence comments starting with /*! are preserved.
ASI safety — JavaScript's Automatic Semicolon Insertion rules mean some newlines are significant. The minifier preserves them where necessary to prevent broken code.
String preservation — content inside string literals, template literals, and regex patterns is never modified.