JavaScript Beautifier & Formatter
Format, beautify, and organize minified or messy JavaScript code with proper indentation and syntax highlighting
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What Is a JavaScript Beautifier?
A JavaScript beautifier (also called a JS formatter or pretty printer) takes minified, compressed, or poorly formatted JavaScript code and transforms it into clean, readable source code with proper indentation, line breaks, and consistent spacing. It is the reverse of minification.
When you receive minified JavaScript from production bundles, third-party libraries, or browser DevTools, it appears as a single long line that is nearly impossible to read. A beautifier restores the code's structure so you can understand, debug, and modify it effectively.
When to Beautify JavaScript
- Debugging production code -- inspect minified bundles to find and fix issues
- Analyzing third-party scripts -- understand how external libraries and widgets work
- Code review -- clean up inconsistent formatting before reviewing or committing
- Learning from source code -- read open-source JavaScript in a structured format
- Restoring readable code -- recover formatting from minified backups or copied snippets
Supported JavaScript Features
This beautifier handles all modern JavaScript (ES6+) syntax including:
- Arrow functions:
const fn = (x) => x * 2 - Template literals:
`Hello, ${name}!` - Destructuring:
const { a, b } = obj - Spread/rest operators:
...args - Async/await:
async function fetchData() { await ... } - Classes:
class Foo extends Bar { ... } - Modules:
import/exportstatements - Optional chaining:
obj?.prop?.method() - Nullish coalescing:
value ?? defaultValue
Formatting Options Explained
Indent Size controls how many spaces (or tabs) are used for each nesting level. 2 spaces is common in the JavaScript community (used by Airbnb, Standard style guides), while 4 spaces is the default in many editors.
Quote Style lets you normalize all string quotes to single or double. Single quotes are preferred by many JavaScript style guides, while double quotes are the JSON standard and common in JSX.
Bracket Style determines where opening braces { are placed. "Same Line" (K&R style) puts the brace on the same line as the statement, which is the dominant convention in JavaScript. "New Line" (Allman style) puts it on its own line, common in C# and some enterprise codebases.
Ensure Semicolons adds semicolons at the end of statements. While JavaScript has automatic semicolon insertion (ASI), explicit semicolons prevent subtle bugs and are required by most style guides.
Frequently Asked Questions
A JavaScript beautifier formats minified or messy JavaScript code by adding proper indentation, line breaks, and consistent spacing. It makes code readable and maintainable by structuring functions, objects, arrays, and control flow in a clean, organized format. This is especially useful when working with minified production code or cleaning up inconsistently formatted files.
Paste your minified JavaScript into the input field, choose your formatting preferences (indent size, semicolons, quote style, bracket placement), and click Format JS. The beautifier will automatically add line breaks, indentation, and spacing to make the code readable. It handles all modern JavaScript features including arrow functions, template literals, destructuring, and async/await.
Beautifying (formatting) adjusts the visual appearance of code -- indentation, spacing, and line breaks -- without changing its behavior. Linting analyzes code for potential errors, bad practices, and style violations. A beautifier makes code look consistent, while a linter helps you find and fix bugs. Many teams use both: a formatter like Prettier for style, and a linter like ESLint for code quality.
Yes, you can customize indent size (2 spaces, 4 spaces, 8 spaces, or tabs), choose between single and double quotes, control semicolon insertion, and select bracket placement style (same line or new line). These options let you format JavaScript according to popular style guides like Airbnb, Standard, or Google, or your team's own conventions.