JS Unminify & Beautify
Beautify and format minified JavaScript instantly. Make compressed, unreadable JS human-readable again. Supports ES5, ES6, ES2015+ and all modern JavaScript syntax.
Everything You Need to Beautify JS
A powerful browser-based JavaScript unminifier with smart formatting, zero dependencies, and complete privacy.
Smart Beautification
Intelligently reformats compressed JavaScript with proper indentation, line breaks, and spacing for immediate readability.
Configurable Indent
Choose between 2 spaces, 4 spaces, or tabs. Match your team's style guide or personal preference exactly.
100% Private
All processing happens in your browser. Your code is never uploaded, transmitted, or stored anywhere. Works offline too.
Instant Results
Beautify any size JavaScript file in milliseconds, directly in the browser with no backend required.
ES5 - ES2020+ Support
Handles arrow functions, template literals, destructuring, async/await, optional chaining, and all modern syntax.
Download Output
Save your beautified JavaScript directly as a .js file with one click.
View Source
Inspect the original source code of any JavaScript file with ease.
Code Inspection
Examine the structure and behavior of your JavaScript code with built-in debugging tools.
How to Unminify JavaScript
Beautify your minified JS code in four simple steps.
Paste Minified Code
Copy your minified or compressed JavaScript and paste it into the input area above.
Choose Formatting
Select your preferred indent size (2 spaces, 4 spaces, or tabs) and any additional formatting options.
Click Unminify JS
Press the orange Unminify JavaScript button to instantly format your code.
Copy or Download
Copy the beautified result to your clipboard or download it as a .js file.
What is JavaScript Unminification?
JavaScript unminification — also called JS beautification or pretty-printing - is the process of reformatting compressed, minified JavaScript code into a human-readable form. Minified JS strips out all whitespace, comments, and newlines to reduce file size, but makes the code nearly impossible to read or debug.
The JS Unminify tool reverses this process by re-adding proper indentation, line breaks, and spacing so you can understand, audit, or modify the code. It's an essential tool for developers who need to inspect third-party scripts, debug production builds, or study minified libraries.
When Should You Unminify JavaScript?
- Debugging a production JS bundle
- Auditing third-party scripts
- Learning from minified libraries
- Code review of compressed files
- Recovering lost source code structure
- Inspecting bundled vendor scripts
Unminify vs. Source Maps
Source maps are the ideal way to debug minified code — they map minified code back to the exact original source, preserving original variable names and file structure. However, source maps are often not available for third-party libraries or production builds you don't control. In those cases, a JS beautifier like this tool is the best option for restoring readability.
Limitations of Unminification
While this tool perfectly restores code formatting, it cannot recover original variable names that were mangled during the minification/obfuscation process. If a minifier renamed calculateTotal to a, the beautifier will output readable code with a — the semantic meaning of the name is lost without a source map.
Frequently Asked Questions
JavaScript unminification is the process of reformatting compressed or minified JS code to make it human-readable again. It restores proper indentation, line breaks, and spacing that were removed during minification. The result is code that has the same functionality but is much easier to read, understand, and debug.
No. If the original minifier used variable name mangling (renaming variables to short names like a, b, c), those original names are permanently lost unless you have access to the original source code or a source map. This tool only restores formatting — it cannot reverse semantic obfuscation.
Absolutely. All processing happens entirely in your browser using client-side JavaScript. Your code is never uploaded to any server, never logged, and never stored. You can safely use this tool with proprietary code, production scripts, or confidential JavaScript. It even works offline once the page has loaded.
Yes. The tool handles ES5, ES6/ES2015, ES2016 through ES2020 and beyond — including arrow functions, template literals, destructuring, classes, async/await, optional chaining (?.), nullish coalescing (??), and all modern JavaScript features.
Unminification restores code formatting (whitespace, indentation, line breaks) that was removed purely for file size reduction. Deobfuscation attempts to reverse intentional obfuscation — techniques designed to make code hard to understand, like renaming all variables to single characters, encoding strings, or inserting dead code. This tool handles unminification; full deobfuscation requires more advanced techniques and often manual work.
No. Unminified JavaScript files are larger and load slower. This tool is intended for development, debugging, and code inspection purposes only. For production, always serve minified JavaScript. Use the companion JS Minify tool to compress your final output before deployment.