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JavaScript Minifier — Compress & Shrink JS With Terser

Minify JavaScript with terser. Mangle, compress, comment policies — and a before / after size comparison.

Free No signup Client-side Privacy friendly Updated

Size:

Size: · saved %

Working…

How to use

  1. 1 Paste your JavaScript on the left.
  2. 2 Toggle Mangle / Compress and pick a comment policy.
  3. 3 Click Minify — see before / after size at a glance.

Why use this tool

  • Real terser engine — same minifier used by webpack, Rollup, and Vite.
  • Lazy-loaded — terser is fetched only when you click Minify, keeping the page light.
  • Side-by-side size comparison so you can see exactly what you saved.
  • Pure client-side — your source never leaves the browser.

Frequently asked questions

What is the difference vs obfuscation?

Minifying shortens names and compresses syntax for performance. Obfuscation goes further — flattens control flow, encodes strings, injects dead code. See the <a class="underline" href="/js-obfuscator">JS Obfuscator</a>.

Will it run on modern JS?

Yes — terser supports ES2020+ syntax including optional chaining, BigInt, top-level await.

Need to pretty-print it back?

Use the <a class="underline" href="/javascript-formatter">JavaScript Formatter</a> to reverse the layout (not the mangling).

What is JavaScript Minifier?

A JavaScript Minifier is a tool that compresses JavaScript source code to reduce its file size for faster delivery. Built on terser, it offers control over name mangling, compression, and comment policies, and shows a before-and-after size comparison. Running entirely in the browser, it minifies code client-side so scripts are never uploaded to a server.

Summary

JavaScript Minifier is a free 開発者 utility by Zerethon Tools. Minify JavaScript with terser. Mangle, compress, comment policies — and a before / after size comparison. Runs entirely in the browser — no signup, no upload.

Category
開発者
Pricing
Free
Privacy
Browser-based
Signup
Not required

Privacy

Your data never leaves your browser unless explicitly stated. JavaScript Minifier runs entirely client-side — no server upload, no logging, no tracking of your input.

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