JavaScript Beautifier / Formatter

Format and beautify minified JavaScript into clean, readable code with proper indentation.

Free to use. Runs in your browser.

Paste minified JavaScript and click Beautify to format it with proper indentation, line breaks, and spacing. Formatting runs in your browser after the page loads.

Input JavaScript

Indent

Why Beautify JavaScript?

Minified JavaScript is designed for machines, not humans. Variable names compressed to single letters, all whitespace stripped, entire libraries on a single line, it's fast to download but impossible to debug. A JS beautifier reverses this process, adding indentation and line breaks so you can actually read the code.

You'll reach for a beautifier when debugging production issues (reading minified error stack traces), reviewing third-party scripts (what does that analytics snippet actually do?), or reformatting code that someone pasted without indentation. It's a development tool you use more often than you'd expect.

This tool handles common JavaScript patterns including strings, objects, arrays, and nested blocks. For advanced formatting with AST-based precision and opinionated style rules, tools like Prettier are better suited. For quick reformatting of minified code, this gives you a readable first pass.

JavaScript Formatting Conventions

Convention	Standard	Why It Matters
Indentation	2 spaces (most JS projects)	Keeps deeply nested callbacks and promises readable
Semicolons	Required (Standard JS) or omitted (no-semi)	Team preference, be consistent, ASI can cause bugs
Quotes	Single quotes (Airbnb) or double (Standard)	Pick one, enforce with a linter, never mix
Braces	Same-line opening brace (K&R style)	Nearly universal in JS, Allman style is rare
Line length	80-120 characters	Prevents horizontal scrolling in code review
Trailing commas	Required in modern configs	Cleaner git diffs, adding an item doesn't touch the previous line

What this means for you: Formatting conventions are about consistency, not correctness. The specific choices matter less than everyone on the team following the same rules. Use ESLint + Prettier in your project for automated enforcement.

When to Use Different Formatting Tools

This online beautifier

Quick one-off formatting of minified code, third-party scripts, or code snippets from Stack Overflow. No installation or project configuration needed. Useful for reading code, not for enforcing style in a project.

Prettier

The industry standard for automated JS/TS formatting. Opinionated (few config options by design), AST-based (understands code structure), integrates with editors and CI. Use this in your actual project.

ESLint --fix

Fixes formatting AND code quality issues. Catches unused variables, missing error handling, and style violations. ESLint + Prettier together give you formatting + linting in one pass.

Browser DevTools

Chrome DevTools has a built-in "Pretty print" button ({}) in the Sources panel. Click it to format any minified script loaded on the page. Great for debugging production issues in real time.

What Beautifying Can't Fix

Beautifying restores readable formatting, but minification is a one-way process for certain transformations:

Transformation	Reversible?	What You See
Whitespace removal	Yes	Beautifier adds it back perfectly
Comment removal	No	Comments are gone permanently
Variable renaming (mangling)	No	calculateTotal → a, readable names are lost
Dead code removal	No	Removed code is gone
Constant folding	No	606024 becomes 86400

If you're trying to read heavily mangled production code, source maps are a better approach. Source maps link minified code back to the original source with full variable names and comments intact.

Related Tools

JS Minifier

Minify JavaScript for production

JSON Formatter

Format JSON data structures

HTML Beautifier

Format HTML markup

CSS Beautifier

Format CSS stylesheets

Regex Tester

Test JavaScript regex patterns

Text Diff Checker

Compare code versions

How to use this tool

Paste minified or messy JavaScript into the input area

Choose your preferred indentation (2 or 4 spaces)

Click Beautify and copy the formatted result

Common uses

Reading minified third-party scripts for security review
Debugging production JavaScript via source inspection
Reformatting code snippets from Stack Overflow
Making auto-generated JavaScript readable for editing

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Frequently Asked Questions

What does a JS beautifier do?

It formats minified or compressed JavaScript into clean, readable code with proper indentation and line breaks. Variable names stay minified (it can't reverse those), but the structure becomes visible, blocks, functions, objects, and arrays get their own lines.

Does this handle ES6+ syntax?

This is a pattern-based formatter that handles common JavaScript structures including strings, objects, arrays, blocks, and semicolons. For advanced ES6+ features like template literals, destructuring, and arrow functions, AST-based tools like Prettier produce more accurate results.

Is this safe for production code?

Beautifying only changes whitespace, it doesn't alter logic, variable names, or execution. The formatted code is functionally identical to the input. That said, always test after formatting, especially if you're committing the result.

Why can't I read minified JavaScript?

Production JS is minified to reduce file size. Comments are stripped, whitespace is removed, and variable names are shortened to single characters. A 100KB readable file might become 40KB of single-line code. Beautifying reverses the whitespace part, making the structure readable.

Should I use 2-space or 4-space indentation?

2-space is the standard in most JavaScript and TypeScript projects. React, Vue, Angular, and Node.js ecosystems all default to 2-space. 4-space is more common in Python and older Java-influenced codebases. Pick what your team uses.

What's the difference between a beautifier and a linter?

A beautifier only changes whitespace and formatting. A linter (ESLint) checks for code quality issues, unused variables, missing error handling, bad practices. Use both: Prettier for formatting, ESLint for quality. They solve different problems.

Can I beautify TypeScript?

TypeScript syntax is a superset of JavaScript. This tool will format the JavaScript portions correctly. Type annotations, interfaces, and generics will be preserved as-is. For full TypeScript-aware formatting, use Prettier with the TypeScript parser.

Is my code sent to a server?

Formatting runs in your browser using JavaScript string processing after the page loads. The code you paste is not uploaded by the formatter.

How do I beautify JS in Chrome DevTools?

Open the Sources panel, find the minified file, and click the {} (Pretty Print) button at the bottom of the editor. Chrome will format the code inline, making it debuggable with breakpoints. This is the fastest way to debug production code.

Will beautifying change my code's behaviour?

No. Adding whitespace and line breaks doesn't change how JavaScript executes. The parser ignores whitespace outside of strings. Your beautified code will run exactly the same as the minified version.

Can I beautify obfuscated code?

Beautifying adds structure (indentation, line breaks) but can't reverse obfuscation. Variable names like _0x1a2b stay as-is. String encoding, control flow flattening, and dead code insertion remain. For de-obfuscation, you need specialised tools.

How does this compare to Prettier?

Prettier is an AST-based formatter, it parses your code into a syntax tree and reprints it according to strict rules. This tool is simpler: it adds line breaks and indentation based on brackets, semicolons, and commas. Prettier is better for project use; this is better for quick one-off formatting.

Results are for general informational purposes only and should be checked before use. They are not professional advice. See our Disclaimer and Terms of Service.