Is my code sent to any server?

No. All minification runs in your browser using the Terser library loaded from a CDN. Your code never leaves your device.

What is the difference between Basic and Advanced mode?

Basic mode removes whitespace and comments only. Advanced mode also mangles (renames) local variable and function names to single letters, which can shave off 10–30% more compared to Basic on typical files.

Will minified code still work correctly?

Yes, for standard JavaScript. Advanced mangling is safe for self-contained scripts. Avoid Advanced mode if your code uses eval() or relies on function.name at runtime, as renaming can break those patterns.

Can I minify ES6+ (arrow functions, classes, etc.)?

Yes. Terser fully supports ES2020 syntax including arrow functions, classes, template literals, async/await, optional chaining, and destructuring.

Why does the minified size not change much?

Well-formatted code that already uses short variable names and few comments will see smaller gains. The biggest savings come from heavily commented or generously spaced source files.

JS Minifier

Name: JS Minifier
Availability: InStock
Author: Nham Vu

Paste JavaScript code and get minified output instantly — removes whitespace and comments to shrink file size, all in the browser.

Options: Mode: Remove Comments Keep License Comments

Input

Output

Click Minify to see output

Size Reduction

Copied!

Summary

Paste JavaScript code and get minified output instantly — removes whitespace and comments to shrink file size, all in the browser.

How it works

Paste or type your JavaScript code into the input panel.
Choose a compression level: Basic (whitespace only) or Advanced (mangle variable names).
Click "Minify" to compress the code instantly.
The output panel shows the minified code along with the size reduction.
Copy the result with one click or download it as a .min.js file.

Use cases

Reduce JavaScript bundle size before deploying to production.
Compress third-party scripts that are not already minified.
Verify how much space minification saves for a specific file.
Quickly produce a .min.js version of a utility script.
Speed up page load times by delivering smaller JS payloads.
Minify inline scripts in static HTML pages.

Frequently Asked Questions

Last updated: 2026-06-09 · Reviewed by Nham Vu