Free JavaScript Formatter & Beautifier
Beautify JavaScript in your browser with js-beautify. Indent control, local processing — not a linter or runtime.
Sample JavaScript
About JavaScript Formatter
Pretty-print JavaScript with `js-beautify`’s JS printer. Whitespace only—does not execute or lint your code.
How it works (technical)
Library: `js-beautify` — `import { js as beautifyJs } from 'js-beautify'`. Options used: `indent_size`, `space_in_empty_paren: true`, `preserve_newlines: true`, `max_preserve_newlines: 2`.
Optional GA4 events on format/copy/error (event names only; not a file upload pipeline).
Edge syntax may print oddly—use your bundler’s formatter for production parity.
When to use it
Minified chunks
Unpack a one-line script enough to find a symbol or error line.
Docs and slides
Normalize indentation before pasting into Markdown or slides.
Quick read
Skim structure before opening a larger file in an IDE.
How to Use JavaScript Formatter
- 1Paste your JavaScript code into the input area.
- 2Select your preferred indentation size.
- 3Click "Format JavaScript" to beautify your code.
- 4Copy the formatted result from the output area.
Key Features
- `js-beautify` JS module
- Indent 2 or 4
- Preserve newlines (capped)
- Copy + optional analytics events
Benefits
- •Reflow only—behavior unchanged
- •Source stays in the tab
- •Works beside JSON validator for literals
Frequently Asked Questions
Will formatting change how my JavaScript works?
No, JavaScript formatting only changes whitespace and indentation. Your code will execute exactly the same way.
Can I format TypeScript with this tool?
Basic TypeScript will format correctly since it's a superset of JavaScript. However, some TypeScript-specific syntax may not format perfectly.
What about JSX code?
JSX code will generally format well, though complex JSX structures might need manual adjustments for optimal readability.