Does it rename variables or mangle names?

No. This is a safe "obvious wins" minifier — it removes comments and collapses whitespace but never renames identifiers or rewrites your code, so valid input stays valid.

Are strings and regular expressions kept intact?

Yes. The minifier tracks string literals, template literals and regular-expression literals and copies their contents verbatim, so a comment marker or space inside a string is never touched.

How much smaller will my file be?

It depends on how heavily commented and indented your source is. The tool reports the exact character count and the percentage saved after each run. Comment-heavy, deeply indented code shrinks the most; already-dense code shrinks little.

Will it break minified code if I run it twice?

No. Running it on already-minified code is safe and roughly idempotent — there is little whitespace left to remove, so the output stays valid.

Should I use this for production builds?

It is great for quick inline snippets, email size limits and pasting compact code. For production bundles a full tool like Terser or esbuild also renames variables and does AST-level optimisations, achieving smaller output than whitespace removal alone.

Is my code uploaded anywhere?

No — minification runs entirely in your browser. Nothing is sent to a server, which makes it safe for proprietary code.

JavaScript Minifier — Gera Tools

Q: How does it tell a regex apart from a division sign?

It checks the previous meaningful token. A slash starts a regex only when the prior token cannot end an expression — after operators, brackets, commas, or keywords like return, typeof and in — otherwise the slash is treated as division.

Minify JavaScript in your browser

Paste any JavaScript to strip comments and collapse whitespace down to a compact single-line result. This is a conservative, dependency-free minifier: it does the obvious size wins without renaming variables or rewriting your code, so valid input always stays valid. Use it for quick snippets, pasting compact code, or trimming a file under an upload or email size limit.

How it works

The minifier scans your source character by character in a single pass and:

removes line comments (//…) and block comments (/*…*/);
copies the contents of string literals, template literals and regular expressions verbatim, so a // or space inside a string is never touched;
collapses runs of whitespace, keeping a single space only where it is needed to separate two word characters (for example return x).

To avoid mangling regular expressions, it tracks the last meaningful token: a / starts a regex only when the previous token cannot end an expression (after operators, brackets, or keywords such as return, typeof and in), otherwise it is treated as division. After minifying it reports the new character count and the percentage saved.

Example

This input:

// Greets a user
function greet(name) {
  const greeting = "Hello, " + name + "!";
  return greeting;
}

becomes:

function greet(name){const greeting="Hello, "+name+"!";return greeting;}

The comment is gone, indentation is collapsed, the space inside "Hello, " is preserved, and the space in return greeting is kept because both sides are word characters.

Everything runs locally — nothing is uploaded, which keeps proprietary source private.