JavaScript Formatter & Beautifier
Free online JavaScript formatter, beautifier, and validator. Beautify, clean, format, and minify messy or compressed JavaScript code with customizable brace styles, syntax error checking, and code compression metrics. 100% client-side execution for safe, private development.
Input JavaScript
Formatted / Minified Output
Click "Format" or "Minify" to see beautified JavaScript.
About JavaScript Formatter & Beautifier
Free online JavaScript formatter, beautifier, and validator. Beautify, clean, format, and minify messy or compressed JavaScript code with customizable brace styles, syntax error checking, and code compression metrics. 100% client-side execution for safe, private development.
What is JavaScript Formatter?
JavaScript Formatter & Beautifier is a lightweight, responsive developer tool that formats, indents, and structures raw or minified JavaScript and ECMAScript code. It enforces readable brace placement, spaces around operators, consistent indentation, and validates syntax errors before execution. Everything runs locally in your browser with zero latency and complete data privacy.
Key Features
- Instant Code Formatting: Automatically beautify JavaScript with 2 spaces, 4 spaces, or Tabs.
- Customizable Brace Styles: Support for standard 1TBS (collapse), Allman (expand), and end-expand brace placement.
- Syntax Validation: Detects invalid syntax with line and column pointers without executing the script.
- Fast JavaScript Minifier: Removes single-line (//) and multi-line (/* */) comments and collapses excess whitespace.
- Code Size Statistics: View total lines, characters, original bytes, and compression savings percentage.
- 100% Client-Side Privacy: Code is never transmitted to an external server or logged in a database.
- 1-Click Export: Copy formatted code to clipboard or download as a clean .js file.
Common Use Cases
- De-obfuscating Code: Make compressed, minified, or bundle-extracted scripts readable for debugging.
- Code Review & Cleanup: Standardize formatting and whitespace across JavaScript functions.
- Syntax Checking: Quickly check whether a snippet of JavaScript contains syntax errors before pasting into a codebase.
- Quick Minification: Reduce JavaScript file sizes for fast web snippets or bookmarklets.
- API Script Testing: Clean up and format async fetch routines, event handlers, and data transformation scripts.
How to Use This Tool
- Paste your JavaScript code into the input editor or click "Sample" to load an example function.
- Select your preferred indentation size (2 spaces, 4 spaces, or tabs) and brace style.
- Click "Format" to beautify the code, or click "Minify" to strip comments and compact the code.
- Click "Validate" to check your code for syntax correctness.
- Copy the result to your clipboard with one click or click "Download" to save as a .js file.
Frequently Asked Questions
Is it safe to format proprietary or sensitive JavaScript code here?
Yes. Utilbox processes all JavaScript formatting and validation strictly on your computer using client-side JavaScript. No code is ever uploaded to a server.
Does this tool support modern ES6+ features?
Yes. Modern ECMAScript features including arrow functions, async/await, template literals, destructuring, and class syntax are fully supported.
How does the syntax validator work?
The validator parses the code structure to ensure syntactic correctness without actually executing any statements. If there is a syntax error, it reports the exact error message and line number.
Can I choose different indentation and brace styles?
Yes. You can switch between 2 spaces, 4 spaces, or Tabs, as well as Collapse (1TBS), Expand (Allman), and End-Expand brace styles to match your project guidelines.