Free Online JavaScript Formatter & Beautifier — clean up messy or minified JS instantly

JavaScript Formatter — Free Online Tool

Beautify and re-indent JavaScript online, free. JavaScript is the programming language of the web, running in browsers and Node.js. This formatter re-indents minified or messy JavaScript with consistent spacing so it is readable and diff-friendly — processing runs in your browser with nothing uploaded.

🚀 Why use this JavaScript Formatter tool?

It expands compressed JavaScript back into a clean, consistently indented form without changing its meaning. 100% free, no registration, and complete privacy — everything runs locally in your browser, so your data never touches a server.

Key Features

Instant beautify

Paste minified or messy JavaScript and get clean, indented output immediately — no upload wait.

📐Consistent indentation

Normalises spacing and nesting so the whole file follows one style, ideal before committing or reviewing.

🔒100% private

Your JavaScript is formatted locally in JavaScript; nothing is logged, stored, or sent to a server.

🆓Free, no signup

Unlimited formatting with no account or quota, on desktop and mobile.

Popular Use Cases

Code review & diffs

  • Make minified JavaScript readable
  • Get clean line-by-line diffs
  • Spot structure at a glance

Where JavaScript is used

  • web applications
  • Node.js services
  • build scripts & automation

Debugging

  • Un-minify third-party JavaScript
  • Trace a rule or statement
  • Understand generated output

What It Handles

Structure

  • Nesting & blocks
  • Comments preserved
  • Whitespace normalised

Output

  • Consistent indentation
  • Readable line breaks
  • Copy or download

Workflow

  • Load an example
  • Re-format any input
  • Runs offline after load

Sources & References

Frequently Asked Questions

How do I format JavaScript online?

Paste your JavaScript into the input box and click Format. The formatter runs instantly in your browser and shows the result on the right — no upload, no signup, no installation.

Is this JavaScript formatter free?

Yes. The JavaScript formatter is completely free with no limits, no account, and no watermark. All processing happens locally in your browser for privacy.

Is my JavaScript sent to a server?

No. Your JavaScript never leaves your device — it is processed locally in JavaScript. We don't upload, log, or store your input, so it's safe for proprietary code and config.

Does formatting change how my JavaScript works?

No. Formatting only adds indentation and line breaks for readability; it does not change the meaning or behaviour of your JavaScript.

Can I use the JavaScript formatter on mobile?

Yes. The tool is fully responsive and works on phones, tablets, and desktops — just open it in any modern browser.

🎓 Pro Tips

  • Tip 1: Format JavaScript right before committing so diffs show real changes, not whitespace noise.
  • Tip 2: Beautifying does not validate logic — pair it with a linter for JavaScript to catch errors.
  • Tip 3: Authoritative reference: ECMAScript (TC39) — https://tc39.es/ecma262/.