JavaScript Formatter

Prettier does not just add line breaks. It parses the code into a syntax tree, throws away the original layout, and prints the tree again using consistent rules. Lines longer than the chosen width are wrapped at the most natural point, such as between function arguments or object properties, and short expressions are kept on one line. Because the output depends only on the code and the options, formatting the same code twice gives exactly the same result, which is why teams use it to end arguments about style.

The defaults match Prettier's own defaults, which most open-source projects use. Change them to match your project's style.

Minified scripts from websites are squeezed onto one line to load faster. Pasting such code here spreads it over many readable lines with proper indentation, which helps when you need to debug a library, inspect what a script does, or understand a bundle. Formatting cannot restore the original variable names if the minifier shortened them to single letters, but the structure of the code becomes clear again.

The formatter must parse the code completely before it can print it. If there is a missing bracket, an extra comma in the wrong place or a stray character, it stops and shows the message with the line and column, and the input is marked at that spot. Pick the right language first: TypeScript-only syntax such as as casts and enums is an error when JavaScript is selected, code is an error when JSON is selected, and comments are not allowed in strict JSON.

This page uses Prettier 3, the same formatter that runs in VS Code, WebStorm and most build pipelines. With the same options, the code you format here matches what your editor's Prettier extension produces, so you can paste the result into your project without creating noisy changes.