Category: Developer

JavaScript Formatter

Format and beautify JavaScript with configurable indentation, quotes and semicolons.

Runs in your browserProcessed locally. Your input never leaves your device.

Layout
Output style

Details

About this tool

Paste JavaScript and receive consistently formatted code using Prettier's JavaScript parser. Choose the indentation, preferred line length, quote style and whether statements should end with semicolons.

The formatter parses the program before printing it, so strings, comments, template literals and nested expressions are handled as syntax rather than guessed from punctuation. Invalid input is reported with its location whenever the parser provides one.

Formatting runs locally in the browser. Your source code is not sent to the server.

Keep going

  • Format TypeScript, interfaces and type annotations with the correct parser.

    Runs in your browserDeveloper
  • Format, indent and beautify JSON.

    Runs in your browserDeveloper
  • Format and beautify HTML fragments or full documents with HTML-specific controls.

    Runs in your browserDeveloper

Good to know

Questions people actually ask

Is this a real JavaScript parser?
Yes. The tool uses Prettier's JavaScript parser, not regular expressions or a generic indentation algorithm.
Is the source code uploaded?
No. Parsing and formatting run in the browser. The language engine is loaded on demand and the source stays on the device.
Can formatting change program behaviour?
The formatter is designed to preserve the parsed program while normalising quotes and semicolons. Review a diff before committing, especially when a repository enforces different style rules.