JavaScript Beautifier
Format and beautify JavaScript code with proper indentation
JavaScript Beautifier
Format and beautify your JavaScript code with proper indentation and spacing
Formatting Options
Privacy: All JavaScript beautification happens in your browser. No data is sent to any server.
Your Privacy is Protected
All processing happens entirely in your browser. No data is stored, transmitted, or tracked. Your information remains completely private and secure on your device.
About JavaScript Beautifier
A JavaScript beautifier (also called a JavaScript formatter or JS prettifier) is an essential development tool that transforms minified, compressed, or poorly formatted JavaScript code into clean, readable, properly indented code that follows standard formatting conventions. When JavaScript is minified for production to reduce file size, it becomes an unreadable single line of code. When copying code from various sources, the formatting is often inconsistent or completely absent. Our JavaScript beautifier instantly restructures your code with consistent indentation, proper spacing around operators, organized brace positioning, and logical line breaks that make the code structure immediately apparent. The tool handles modern JavaScript syntax including ES6+ features like arrow functions, template literals, destructuring, async/await, classes, and modules. It formats complex nested structures, properly indents callback chains, organizes object and array literals, and maintains comment positions. This is invaluable for debugging minified production code, learning from obfuscated JavaScript, maintaining coding standards across teams, preparing code for version control, and making inherited codebases readable. Whether you're reverse-engineering a script, cleaning up auto-generated code, or establishing consistent formatting across a project, the JavaScript beautifier transforms unreadable code into maintainable, professional JavaScript that any developer can understand and modify.
Key Features
Smart Auto-Formatting
Automatically format JavaScript with intelligent rules for indentation, spacing, and line breaks. The beautifier understands JavaScript syntax deeply, properly handling objects, arrays, functions, classes, conditionals, loops, and all modern ES6+ features with contextually appropriate formatting.
Customizable Style Options
Choose between different coding styles: spaces vs tabs, indentation level (2 or 4 spaces), brace positioning (same line vs new line), quote style (single vs double), and more. Configure formatting to match your team's style guide or personal preferences.
ES6+ and Modern Syntax Support
Fully supports modern JavaScript features including arrow functions, template literals, destructuring assignments, spread operators, async/await, generators, modules (import/export), classes, optional chaining, nullish coalescing, and all other ES2015-ES2023 syntax.
JSX and React Formatting
Properly format JSX syntax used in React applications. The beautifier understands JSX elements, props, children, fragments, and expressions, applying appropriate indentation and spacing that makes component code readable and maintainable.
TypeScript Support
Format TypeScript code including type annotations, interfaces, enums, generics, and TypeScript-specific syntax. The beautifier preserves type information while applying formatting rules, making TypeScript code as readable as JavaScript.
Comment Preservation
Maintains all comments (single-line // and multi-line /* */) in their proper positions while formatting code. Comments are repositioned appropriately when code structure changes, ensuring documentation stays with the code it describes.
AST-Based Formatting
Uses Abstract Syntax Tree (AST) parsing to understand code structure rather than simple text manipulation. This ensures correct formatting even for complex nested structures, and prevents formatting errors that could change code behavior.
Batch File Processing
Format multiple JavaScript files or large codebases at once. Upload entire folders or multiple files, and the beautifier processes them all while maintaining folder structure, perfect for cleaning up legacy projects or enforcing standards across repositories.
How to Use the JavaScript Beautifier
Paste your minified, compressed, or poorly formatted JavaScript code into the input editor
You can paste code from any source—minified production files, copied snippets, or inconsistently formatted scripts.
Configure formatting preferences in the options panel
Choose indentation style (spaces or tabs), indentation size (2 or 4), brace style (K&R, Allman, etc.), quote style, and other formatting rules to match your coding standards.
Select any advanced options if needed: preserve empty lines, wrap long lines at specific length, format JSX/React code, or apply specific rules for arrays and objects
These options fine-tune the output format.
Click 'Beautify JavaScript' to format your code
The tool processes the input using AST parsing and applies all selected formatting rules, displaying the beautifully formatted result in the output editor.
Review the formatted code with syntax highlighting
Check that all braces are properly aligned, indentation is consistent, and the code structure is clear. Verify that formatting matches your expectations.
Copy the beautified JavaScript to your clipboard with one click, or download it as a .js file if you need to save it
The formatted code is now ready for development, debugging, or version control.
For projects with many files, use the batch processing feature to format multiple files at once
Upload a folder, apply formatting rules, and download the formatted files maintaining the original directory structure.
Integrate the beautifier into your development workflow
Format code before commits, use it to clean up legacy code, or apply it to minified third-party libraries when you need to understand their implementation.
Frequently Asked Questions
Will beautifying change how my JavaScript works?
No! Beautifying only changes formatting and whitespace—it never modifies code logic, variables, functions, or behavior. The resulting script executes exactly the same as the original. However, if your original code had syntax errors, beautifying might make them more apparent (but doesn't create them). It's purely cosmetic for readability.
Can beautifying fix JavaScript errors?
No, beautifiers only format code—they don't fix syntax errors or logical bugs. If your JavaScript has errors like missing semicolons, unmatched braces, or undefined variables, you'll need to fix those manually or use a linter. However, beautifying often makes errors easier to spot by properly structuring and indenting the code.
Should I beautify code before or after minification?
Maintain beautifully formatted JavaScript during development, then minify only for production deployment. Keep source files formatted for readability, use version control for the beautified versions, and only minify during the build process. Never beautify code that's meant for production—keep a separate source version for development.
What's the difference between beautify and minify?
Beautifying adds formatting (indentation, line breaks, spacing) to make code human-readable. Minifying removes formatting and shortens code to reduce file size. They're opposite operations: beautify for development and maintenance, minify for production deployment. You toggle between both depending on whether you're developing (beautify) or deploying (minify).
Does beautifying affect file size?
Yes, beautified JavaScript is significantly larger than minified because it includes indentation, line breaks, and spacing. Files can be 30-70% larger. This is why you keep beautified code for development and serve minified code to users. Use build tools to automatically minify during production builds.
Can I customize beautifier settings?
Yes! Configure indentation type and size, brace positioning style, quote style (single vs double), operator spacing, line length limits, and many other options. You can match popular style guides like Airbnb, Standard, Google, or create custom configurations. Save presets for consistent formatting across projects.
Will it preserve my comments?
Yes, JavaScript beautifiers preserve all comments while formatting code. Both single-line (//) and multi-line (/* */) comments are maintained and repositioned appropriately based on the code structure. This ensures you don't lose documentation when beautifying code.
How is this different from my editor's auto-format?
While IDEs have built-in formatting, online beautifiers offer advantages: no software installation, consistent formatting across different editors, works with any code source without opening files, accessible from any device, and provides specific JavaScript formatting focus. Perfect for quick formatting tasks or when you don't have access to your usual editor.
Use Cases
- Debugging Minified Production Code: When troubleshooting issues in production, beautify minified JavaScript to understand what the code is doing. Transform single-line minified code into readable format where you can set breakpoints, follow execution flow, and identify the source of bugs. Essential for hotfixes and production debugging.
- Code Review and Team Collaboration: Ensure consistent JavaScript formatting across your development team before code reviews. Beautify all code to a standard format, eliminating formatting debates and allowing reviewers to focus on logic and implementation rather than style inconsistencies. Improves review efficiency and code quality.
- Learning from Third-Party Code: Study JavaScript libraries, frameworks, or plugins by beautifying their minified distribution files. Understand how popular libraries implement features, learn optimization techniques, and adapt patterns to your own projects. Transform compressed vendor code into readable, educational examples.
- Legacy Code Modernization: Clean up old JavaScript codebases with inconsistent or absent formatting. When inheriting legacy projects with mixed coding styles or no standards, use the beautifier to establish a consistent baseline format. This makes code more maintainable and easier to refactor or extend.
- Version Control Preparation: Format JavaScript files before committing to Git or other version control. Consistent formatting makes diffs more meaningful, simplifies merge conflicts, and creates cleaner commit histories. Integrate beautification into pre-commit hooks to enforce standards automatically.