JavaScript Formatter

1. Paste your JavaScript code into the input box on the left, or click Sample to load a messy example.
2. Choose your preferred indentation (2 spaces, 4 spaces, or tab) and toggle semicolons on or off.
3. Click Format — Prettier will parse your code with the Babel parser and re-emit it with consistent indentation, semicolons, and whitespace.
4. Copy the result with Copy and paste it into your editor.

This tool uses the same Prettier configuration that powers millions of JavaScript projects. The output matches what you would get from running prettier --parser babel in your terminal. ES6+ syntax (arrow functions, destructuring, async/await, optional chaining) is fully supported.

A JavaScript formatter (also called a beautifier or pretty-printer) takes messy, inconsistently-styled JavaScript code and re-emits it with uniform indentation, semicolon usage, and whitespace. Formatting does not change the runtime behavior of the code — it only changes how the source text looks. This makes code easier to read, easier to review in pull requests, and free of style debates that waste engineering time.

Prettier is the de facto JavaScript formatter. It is opinionated: it enforces a single canonical style for any given input, which means there is nothing to argue about. Teams adopt Prettier by adding a .prettierrc file to their repo and running it on save in their editor. This tool lets you format ad-hoc code snippets without installing anything.

This formatter is configured for plain JavaScript (Babel parser). TypeScript code with type annotations may not format correctly here. For TypeScript, use a tool that explicitly loads the TypeScript parser. Plain ES6+ JavaScript (including JSX) works perfectly.

No. Prettier is a formatter, not a transpiler. It does not convert arrow functions to regular functions, does not polyfill new syntax, and does not minify. The output is functionally identical to the input — just better-looking. If you need minification, use a minifier like Terser.

No. Prettier runs entirely in your browser on this page. Your code never leaves your device.