JavaScript Formatter

Overview

Beautify your JavaScript — cleanly and privately

Direct answer: A JavaScript formatter re-indents and spaces messy or minified JavaScript so it's readable — consistent indentation, line breaks, and spacing around operators and braces. This one runs entirely in your browser, so your code is never uploaded, and it safely leaves strings, regex, and comments untouched.

Minified bundles, one-line snippets, and inconsistently-styled code are all hard to read. A JavaScript formatter (beautifier) restores a clean, consistent layout: sensible indentation, line breaks between statements, and even spacing around operators, braces, and commas — so you can actually follow the logic.

Paste your JavaScript, press Sample to try it on a real file, or use Open file to read a local .js off your disk. Set the indent to 2 spaces, 4 spaces or a tab and the quote style to auto, single or double, and the tool reformats as you type with syntax highlighting and a live byte count. It tokenises the code rather than pattern-matching it, so strings, template literals, regular expressions and comments are read as what they are and their contents are left exactly as written — only the layout around them changes. Copy and Download both take whichever output is on screen.

As always, privacy leads. All formatting happens in your browser — no server, no upload, no logging, and no tracking of your code. Developers paste proprietary logic, client scripts, and minified bundles; here it never leaves your device. The formatter itself is served from this site, not a CDN, so once the page has loaded the tool keeps working with no internet connection at all — install it and it works on a plane.

The JavaScript Formatter in dark mode: minified source in the cyan Your JavaScript pane on the left with numbered lines, the same code re-indented in the magenta Beautified pane on the right, and a green Formatted pill reading 11 lines, 497 B in, 611 B out — Cyan is what you pasted, magenta is what the tool made of it

Two honest points worth stressing. First, beautifying is cosmetic — it changes whitespace and style, not behavior. Crucially, it is not de-obfuscation: if code was minified, variables renamed to a, b, c stay renamed; the formatter restores readable layout, not meaningful names or original comments. Second, it's not a linter or transpiler — it won't catch bugs, apply your ESLint rules, or convert TypeScript/JSX to JavaScript; it beautifies plain JS.

Minify here is the safe kind. Switch the output to Minify and the tool strips comments and redundant whitespace and nothing else — it never renames a variable, and it never removes a line break that automatic semicolon insertion depends on. It then re-parses its own output: if source that parsed comes back as source that does not, the tool says so and hands your input back unchanged rather than quietly giving you broken code. For the aggressive kind — renaming, dead-code removal, real production savings — use the JavaScript Minifier.

The same file with the output switched to Minify: comments and indentation gone, the string https://example.com/v1//items still intact, and the stat line reading Input 497 B, Output 426 B, Change -14 percent — Safe minify: comments and whitespace go, a URL inside a string does not

For other languages, see the HTML Formatter, CSS Formatter, and JSON Formatter.

Use cases

When a JavaScript formatter helps

Unminifying. Make a minified script readable for inspection.
Debugging. Follow logic with clean indentation.
Cleaning snippets. Tidy pasted or inconsistent code.
Reading libraries. Beautify a compressed vendor file to study it.
Sensitive code. Format proprietary JS without uploading it.

The formatter on a 390-pixel phone: the Beautify and Minify segment across the top, indent and quote buttons below it, and a tab strip switching between Your JavaScript and Result so one pane fills the screen at a time — On a phone the two panes become a tab strip — one full-width pane at a time

Guide

How to format JavaScript

Paste or load your JavaScript

Type it, paste it, or open a local file (read in-browser, not uploaded).

Choose your indentation

2 spaces, 4 spaces, or a tab.

Format

The tool re-indents and spaces the code consistently and highlights the syntax.

Check strings and regex

Their contents are preserved exactly; only layout changes.

Copy or download

Grab the formatted (or minified) output. Nothing is sent anywhere.

Realistic example

Paste function add(a,b){return a+b} and it becomes a properly indented, spaced function you can read at a glance — with return a + b; on its own line inside braces.

Advanced tip

Beautifying a minified library helps you read it, but don't expect the original variable names back — minification discards them, and no formatter can restore them.

Common mistake to avoid

Don't rely on the formatter to catch errors; it lays out code, valid or not. Use a linter (like ESLint) for correctness.

To shrink JS for production, use the JavaScript Minifier.

Good to know

What to keep in mind

Zero-knowledge and private. Formatting runs in your browser — nothing uploaded, logged, or tracked, and it works offline.
Cosmetic only. It changes whitespace and style, not behavior.
Beautify is not de-obfuscate. Minified variable names stay renamed; only layout is restored.
It shows you the parse error, but it is not a linter. Source that does not parse is still laid out, with the error named beneath the panes — useful for finding a stray brace, no substitute for ESLint.
Not a linter or transpiler. It won't find bugs, apply ESLint rules, or convert TypeScript/JSX.
Large scripts run locally. Very big bundles are limited by your device, since there's no server.

A function missing a closing brace: the formatter has re-indented it anyway in the magenta pane, the status pill reads Syntax error in red, and a panel below reads 1 problem, Unexpected token close-parenthesis — Broken source is still laid out — and the parse error is named rather than swallowed

Support

Frequently Asked Questions

How do I beautify or format JavaScript?

Paste your JavaScript (or load a local file), choose an indentation of 2 spaces, 4 spaces, or a tab, and the tool re-indents the code and adds consistent spacing around operators, braces, and commas. A minified or cramped script becomes readable, with each statement laid out clearly. Then copy or download the result — nothing leaves your browser.

Does this upload my code, and does it work offline?

No upload, and yes it works offline. All formatting happens in your browser using JavaScript — there's no server receiving your code, no logging, and no tracking of your content. That makes it safe for proprietary or client scripts. Once the page has loaded it keeps working with no internet connection, which you can confirm in your browser's network tab.

Does beautifying change how my code behaves?

No. Beautifying only changes whitespace and layout — indentation, line breaks, and spacing — which JavaScript ignores between tokens, so the behavior is identical. The tool preserves the contents of strings, template literals, regular expressions, and comments exactly, so nothing that affects execution is altered. Your code runs the same before and after; it's just easier to read.

Can it de-obfuscate or "unminify" minified JS?

It can restore readable layout, but not original names. Beautifying a minified file re-indents and spaces it so you can follow the structure, but variables that minification renamed to a, b, c stay that way, and stripped comments don't come back. So it makes minified code readable, not de-obfuscated. No formatter can recover information that minification discarded.

What indentation should I use?

It's a style choice. 2 spaces is a very common JavaScript default and keeps code compact; 4 spaces is more spread out; a tab lets each editor set its own width. Indentation is purely cosmetic and doesn't affect execution, so pick whatever matches your project's or team's style guide. Many teams enforce one via a formatter like Prettier.

What's the difference between formatting and minifying JS?

Formatting (beautifying) adds indentation and spacing to make code readable; minifying takes them away to make the file smaller. You beautify while developing and minify for production. The Minify switch here is the safe kind: it removes comments and redundant whitespace and nothing else, never renaming a variable and never dropping a line break that automatic semicolon insertion depends on, and it re-parses its own output before showing it to you. Aggressive minification — renaming, dead-code removal, the real production savings — is the JavaScript Minifier.

Is this a linter — will it find bugs?

No. A formatter only changes how code looks; it doesn't analyse what it does. It won't catch bugs, undefined variables, unused imports, or style-rule violations, and it won't apply your ESLint configuration. For that, use a linter like ESLint alongside a formatter. Beautifying and linting are complementary but separate jobs.

Does it handle template literals, regex, and comments?

Yes — carefully. The contents of template literals (backtick strings), regular expressions, and comments are preserved exactly, because reformatting inside them could change their meaning or break the code. The formatter only re-lays-out the surrounding structure. This is why a good beautifier parses the code rather than blindly reformatting text.

Does it work with TypeScript or JSX?

It's built for plain JavaScript. TypeScript type annotations and JSX are supersets/extensions of JS, so a JS-only formatter may not lay them out perfectly and definitely won't strip types or compile JSX — that's a transpiler's job (like the TypeScript compiler or Babel). For TS/JSX specifically, use a formatter that understands them, such as Prettier with the right parser.

Can I load a JS file instead of pasting?

Yes. You can open a local .js file and the tool reads it directly in your browser with the FileReader API — the contents load into the editor without being uploaded anywhere. This is handy for larger scripts or ones you'd rather not copy and paste, and it's exactly as private as pasting the code by hand.

Can it format very large scripts or bundles?

Usually yes. Because it runs locally, the limit is your device's memory and CPU rather than a server cap, and modern browsers handle large files well. Very large minified bundles (many megabytes) can be slow to parse and render, but there's no upload size limit from us and nothing is sent anywhere — it's purely a matter of local performance.

Is it free, and are there limits?

Yes, completely free — no payment, no signup, no account, and no usage caps or watermarks. Since everything runs in your browser, there's nothing for us to meter; the only practical limit is your device's performance on very large files. Use it as much as you like, including offline once the page has loaded.

Still have questions?

If you can't find the answer you're looking for, feel free to contact our support team.

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