JavaScript Formatter
Format JavaScript online in your browser with custom indentation. Free, no upload, no account. Pretty-print minified JS as text only - code never executed or stored.
Runs locally in your browser. Your input is not uploaded to DevToolMate servers.
Format only
Formats JavaScript source as text only. Does not evaluate or run your script.
Developer Quick Tips
- Paste or open .js, .mjs, .cjs files, select indentation (0, 2, 4, or 8 spaces), and format instantly in your browser with zero server upload.
- Format minified JavaScript to restore readability. Expand compressed code with proper line breaks and indentation for debugging and code review.
- Handles functions, objects, arrays, template literals, and ES modules as text only - no execution, no eval, no sandboxing required.
- Use Ctrl/Cmd+Enter to format after pasting, then download as formatted.js. Your code stays on your device and is cleared when you close the tab.
- Combine with javascript-minifier: beautify first to read your code, then minify for production. Two separate, complementary tools.
Frequently asked questions
Can I format minified JavaScript online?
Yes. Paste minified or compressed JavaScript and the formatter will expand it with proper indentation and line breaks, making it readable and easier to debug.
Is this a free JavaScript formatter online?
Yes. This is a free online JavaScript formatter that runs entirely in your browser. No server upload, no account, no login required.
What's the difference between format and minify?
Format (beautify) adds indentation and line breaks to make code readable. Minify removes whitespace to shrink file size. This tool formats only. Use javascript-minifier for compression.
Will my JavaScript code be executed or evaluated?
No. This tool processes your code as text only. It does not execute, eval, run, or sandbox your JavaScript in any context - only formats it for readability.
What indentation options are available?
You can choose 0, 2, 4, or 8 spaces per indentation level. Select your preferred style before formatting to match your coding standards or team guidelines.
Is my code uploaded to DevToolMate servers?
No. JavaScript Formatter runs entirely in your browser. Your code never leaves your device, never connects to our servers, and is cleared when you close the tab.
Related tools
- JavaScript Minifier: Free JavaScript minifier that runs browser-local. Minify JS by removing comments and whitespace. No upload, no account, no code execution.
- HTML Formatter: Format HTML online free with pretty-print indentation. Beautify minified markup in your browser, no upload, no account required.