JavaScript Formatter
Format JavaScript to a clean, consistent style.
Runs entirely in your browser — your data is never uploaded to any server.
How it works
- Paste your codeModern JavaScript or JSX.
- Set your styleQuotes, semicolons and line width.
- Copy the resultConsistently formatted code.
What this tool does
- Modern syntax, including async, optional chaining and JSX
- Configurable quotes, semicolons and line width
- Syntax errors reported with a line number
- Nothing is uploaded — proprietary code stays local
Frequently Asked Questions
No. Only formatting changes. The parsed structure of your program is identical.
Plain JavaScript and JSX are supported here. TypeScript-specific annotations may not parse.
The code has a syntax error. The message includes the line number so you can find it.
No, this formats for readability. Minification is a build-time concern.
Privacy and security
Your input is processed by JavaScript running inside your browser. Nothing you paste is sent over the network, logged, or stored — which is what makes this safe to use with production data. If you want to check this yourself: open your browser’s developer tools, switch to the Network tab, and use the tool — you will see no request carrying your file or input leave the page.