Format JavaScript Online
Format JavaScript online with readable indentation so scripts, copied snippets, and bundled code are easier to inspect, debug, and understand. Paste minified or dense JavaScript and the formatter expands functions, conditions, and blocks into clean, readable output.
How to use JavaScript Formatter
Paste or type content into the javascript input panel.
Run the formatter to clean up spacing, indentation, and structure.
Copy or download the formatted result when it looks right.
Why this helps in real workflows
A minified JavaScript file from a production bundle needs to be expanded so you can read the logic and debug a specific function.
A code snippet copied from a browser console, a Stack Overflow answer, or documentation is all on one line and needs formatting.
You are reviewing JavaScript from a third-party embed, widget, or integration and want readable output before inspecting what it does.
Generated JavaScript from a tool or template has inconsistent indentation and needs cleaning up before editing or committing.
Common problems and fixes
The formatter returns an error for JavaScript that seems valid.
The formatter parses JavaScript before reformatting. Syntax errors — missing brackets, unclosed strings, or invalid tokens — will cause it to fail. Check the reported error location and fix the syntax issue in the source first.
Arrow functions or modern syntax are not formatting correctly.
The formatter supports modern JavaScript including arrow functions, template literals, destructuring, and async/await. If a specific construct is not formatting as expected, check whether it is valid syntax — some shorthand or edge-case patterns may need a small adjustment.
The formatted output is significantly larger than the original.
Formatting adds whitespace and line breaks for readability, which increases the character count. This is expected for development use. For production, the code should be minified again before deploying.
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Frequently asked questions
How do I format JavaScript?
Paste your JavaScript into the input box, run the formatter, and copy or download the formatted JavaScript output.
Can this JavaScript formatter clean single-line code?
Yes. It reformats dense or minified JavaScript into a readable structure with consistent indentation and line breaks.
Is this JavaScript formatter free?
Yes. It is free to use in your browser.
Does the JavaScript formatter support modern ES6+ syntax?
Yes. It supports modern JavaScript including arrow functions, template literals, destructuring assignments, spread operators, optional chaining, and async/await.
Will formatting JavaScript change how it runs?
No. Adding whitespace and line breaks does not change the behaviour of JavaScript code. The formatted version is functionally identical to the original.
Can I use this to make sense of obfuscated JavaScript?
Formatting helps with minified code by restoring whitespace and structure. Truly obfuscated code — with variable names replaced by single letters or encoded strings — will be formatted but may still be hard to read, as formatting does not reverse obfuscation.