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Page Utils

JavaScript Formatter

JavaScript Formatter pretty-prints or minifies JavaScript in your browser. Paste a script or snippet, format it locally with Prettier (babel + estree), then copy two-space or compact output. Nothing is uploaded or sent to a remote API. Invalid JavaScript gets a parse error beside the input. This page does not execute code, bundle modules, or claim terser/uglify compression.

Updated

Paste JavaScript and format it locally — pretty-print with consistent indentation for reading and review, or minify with an honest whitespace collapse. Closing the tab drops the workspace; we do not write it to localStorage or send it to a formatter API. This page is a JavaScript formatter / JS beautifier for text you already have, not a bundler and not a TypeScript type-checker.

Formatting runs in the browser with Prettier standalone plus the babel and estree plugins (already on this site for other formatters). If the text cannot be parsed as JavaScript, the page shows an error next to the input instead of guessing at a fix. Identifiers and literals are preserved as written; this page reflows whitespace and indentation, it does not rewrite your logic, tree-shake, or minify with terser.

JavaScript workspace

Pretty

Paste JavaScript (or common JSX-free snippets). Whitespace and indentation only — code is not executed, bundled, or type-checked. Nothing is uploaded.

Output

Whitespace formatter only — not terser/uglify, not a bundler, and not a TypeScript type-checker. Closing the tab drops the workspace. For HTML pages with inline scripts, HTML Minifier keeps <script> bodies safe.

How does the JavaScript Formatter work?

  1. 1. Paste JavaScript

    Drop in a script or snippet. Load example fills a tiny fictional IIFE with a nested object.

  2. 2. Format locally

    The browser runs Prettier (babel parser + estree) in this tab. Nothing is uploaded and no modules are fetched or executed.

  3. 3. Pretty-print or minify

    Choose indented output for reading and review, or a compact whitespace-collapsed form for pasting into a tight field. Logic stays as written; only whitespace and indentation change. Minify is not terser/uglify.

  4. 4. Copy the result

    Copy the formatted JavaScript. Closing the tab drops the workspace. Need HTML, CSS, XML, SQL, or JSON instead? Use the other Developer formatters on this hub.

Questions about JavaScript Formatter

What does this JavaScript formatter do?
It pretty-prints (beautifies) or minifies JavaScript in your browser. Paste a script or snippet, and it reformats whitespace and indentation so code is easy to read — or collapses whitespace for a compact paste. It is a local JavaScript formatter / JS beautifier, not a bundler and not a TypeScript type-checker.
Does it upload my JavaScript?
No. Formatting runs entirely in this tab with Prettier standalone. There is no account, no server-side formatter, and no file upload. The text you paste stays here until you clear it or close the page. We do not write it to localStorage. That is the same privacy rule as HTML Formatter, CSS Formatter, XML Formatter, SQL Formatter, and JSON Formatter on this hub.
Why is there no /js-beautifier/ or /js-formatter/ second URL?
One canonical URL: /developer/javascript-formatter/. The page name matches the Developer formatter family. Queries like "js formatter", "format javascript", and "javascript beautifier" can land here; we do not publish a second /js-beautifier/ stub slug.
What happens if my JavaScript is invalid?
You get a short Prettier parse error next to the input and the output stays empty. The page does not invent missing braces or semicolons. Fix the script in an editor and paste again.
How is this different from HTML Formatter or CSS Formatter on this hub?
HTML Formatter formats HTML markup. CSS Formatter formats stylesheets. This page formats JavaScript with Prettier's babel parser. They share the same privacy rule (local only) but accept different languages — they do not convert between JS, HTML, and CSS.
Does Minify use terser or uglify?
No. Pretty mode is Prettier with two-space indent. Minify is an honest whitespace collapse after a successful Prettier parse — not terser, not uglify-js, and not a claim of production-grade compression. For advanced minify (dead-code elimination, mangling), use a local bundler.
Can it handle TypeScript or JSX?
The parser is babel (classic JavaScript). Some modern syntax that babel accepts may format; full TypeScript type-checking and JSX transforms are out of scope for v1. Prefer plain JavaScript snippets when you need a reliable pretty/minify pass.
Does it execute my code or fetch modules?
No. The formatter never runs your script, never evaluates expressions, and never fetches import or require targets. It only reflows whitespace and indentation in this tab with Prettier. Closing the tab drops the paste — there is no sandbox runner and no remote module fetch.

What else can I open?

These tools run in your browser. Page Utils does not store, upload, or write to localStorage the keys, tokens, or text you paste. Results are a convenience aid, not legal, tax, or security advice.