JavaScript Formatter & Beautifier
Beautify or minify JavaScript code instantly. Supports ES6+, arrow functions, template literals, async/await, and JSX. 100% browser-based.
📝 What This Tool Does
A free online JavaScript formatter that beautifies or minifies your code in the browser. Paste messy, compressed, or inconsistently indented JS and get clean, readable output with proper indentation, line breaks, and brace placement — or compress it into a single line for production deployment.
The formatter handles modern JavaScript (ES6+) including arrow functions, template literals, destructuring, async/await, optional chaining, classes, and JSX syntax. All processing happens locally in your browser — your code is never uploaded to any server.
📋 Example
Before (minified)
const f=async(u)=>{const r=await fetch(u);if(!r.ok){throw new Error(r.status)}return r.json()}After (beautified, 2-space)
const f = async (u) => {
const r = await fetch(u);
if (!r.ok) {
throw new Error(r.status)
}
return r.json()
}⚡ How to Use
- Paste your JavaScript into the input panel (or upload a .js file, or click "Sample")
- Choose Beautify or Minify with the toggle buttons
- Adjust indent size in Settings (2 spaces, 4 spaces, or tab)
- Copy or download the result — keyboard shortcuts: Ctrl+K to copy, Ctrl+S to download
🎯 Use Cases
🔍 Code review
Beautify minified code from a production bundle, third-party script, or browser DevTools so you can actually read it.
🚀 Production prep
Minify your JS to reduce file size by 30–60% before deploying, especially if you don't have a build pipeline set up.
🧹 Cleanup
Fix inconsistent indentation from copy-paste, merge conflicts, or different editor configs. Normalize your codebase to 2-space, 4-space, or tab indentation.
🎓 Learning
Paste compressed code snippets from tutorials and Stack Overflow to see them properly formatted and easier to understand.
🔒 Privacy
- ✓ All formatting runs in your browser using JavaScript
- ✓ Your code is never uploaded, stored, or logged
- ✓ Works offline after the first page load
- ✓ No signup, no ads, no tracking
❓ Frequently Asked Questions
Does formatting change how my JavaScript works?
No. Beautifying only adds or rearranges whitespace and line breaks, which JavaScript engines ignore. Your code will run identically before and after formatting. Minifying is equally safe — it removes non-functional characters like comments, extra spaces, and newlines.
Does it support modern JavaScript (ES6+)?
Yes. The formatter handles arrow functions, template literals, destructuring, async/await, optional chaining, nullish coalescing, class syntax, and all modern ES2015+ features. It processes the code as text with syntax-aware parsing, so any valid JS syntax is handled correctly.
What about JSX / React code?
The formatter handles JSX syntax (angle brackets, self-closing tags, embedded expressions). It treats JSX as part of the JavaScript code and indents it along with the rest. For dedicated React/TSX formatting, also check our TypeScript Formatter.
How much does minifying reduce file size?
Typically 30–60% for readable source code. The minifier strips all comments, collapses whitespace, and removes unnecessary line breaks. For example, a 10 KB formatted file might shrink to 4–6 KB. Combined with gzip compression on your server, the savings are even larger.
Is my code sent to a server?
No. All formatting runs locally in your browser using JavaScript string processing. Your code never leaves your machine — nothing is uploaded, stored, or logged. Works offline after the page loads.
Can I upload a .js file?
Yes. Click the upload button in the input panel header to load a .js or .txt file (up to 5 MB). The formatted result can be downloaded as a .js file using the download button in the output panel.