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Free developer tool

JS Unminifier

Turn compact, hard-to-read JavaScript back into clean, formatted code, right in your browser. Paste your minified script on the left, click Unminify JS, and copy the readable result on the right.

Working field

Paste your minified JavaScript and unminify it.

Minified JS Input

Result

Your unminified code appears here.

Your formatted code will show here once you paste a script and click Unminify JS.

This tool is best for reviewing bundled files, debugging production code, and learning from scripts.

Free Online JavaScript Unminifier & Beautifier

Reformat compact, unreadable JavaScript into clean code with proper indentation and line breaks. This tool keeps the workflow simple: paste and unminify on the left, supporting content below, and the sidebar on the left for popular and related tools.

Readable formatting

Adds indentation and line breaks so compressed scripts become easy to read again.

Logic stays intact

Only the layout changes, so your code keeps working exactly the same way.

Modern syntax

Handles ES6 and beyond, including arrow functions, classes, and template literals.

Private by design

Everything runs in your browser, so your code never leaves your device.

How it works

  1. Paste your minified JavaScript into the input on the left.
  2. Click Unminify JS to reformat the code with clean spacing.
  3. Review the formatted output in the result panel on the right.
  4. Use Copy Output to grab the result, or Reset to start over.

Best practices

  • Paste valid JavaScript to get clean, predictable formatting.
  • Unminify before debugging to spot logic issues faster.
  • Keep a backup of the original minified file just in case.
  • Use it to study how third-party scripts actually work.
  • Re-minify your final code before deploying to production.
  • Test the formatted code in a compiler to confirm it still runs.

Frequently asked questions

What does the JS Unminifier do?

It reformats minified or compressed JavaScript code into a clean, readable format by adding indentation and proper line breaks. This makes the code human-readable and easier to debug.

Is this JavaScript Unminifier free to use?

Yes. The tool is 100% free. There are no hidden charges, and you don't need to create an account or download any software to use it.

Can I use this tool for ES6 or modern JS code?

Absolutely. Our tool supports modern JavaScript syntax (ES6, ES7, and beyond), so arrow functions, classes, and template literals are formatted correctly.

Is my code safe and private?

Completely. All unminification happens locally in your web browser. Your code is never sent to our servers, so your intellectual property stays private.

Does unminifying code change how it functions?

No. The tool only changes the visual formatting, like whitespace and indentation. The underlying logic and functionality of your JavaScript stay exactly the same.

Can it de-obfuscate heavily protected code?

While it can make obfuscated code much more readable by fixing the layout, it cannot recover original variable names if they were changed to short, random characters during obfuscation.

Is there a limit on the file size I can paste?

There is no hard limit, but extremely large files may slow down your browser's performance. For most standard scripts and libraries, it works almost instantly.

Why should I unminify my JavaScript?

Unminifying is essential for debugging production errors, performing security audits on third-party libraries, or learning how a specific script works.

How do I turn unminified code back into minified code?

Once you finish editing or reviewing your code, use our JS Minifier tool to compress it back into a production-ready format.

Does this tool work on mobile devices?

Yes. The tool is fully responsive. You can paste and beautify JavaScript code on any modern smartphone or tablet browser.

Need more developer tools? Compress your code back for production with the JS Minifier tool, or run and test your snippets with the JavaScript Compiler tool.