JavaScriptフォーマッター

This is a JavaScript beautifier that reformats minified or messy code with consistent indentation, spacing and line breaks, so it becomes readable again for understanding or debugging.

It is powered by a well-established formatting engine, the same kind of logic editors use, so it handles modern JavaScript syntax and produces clean, conventional output rather than a naive reindent.

Formatting runs entirely in your browser, so your code never leaves your device, which matters for proprietary or sensitive scripts.

Reformatting only changes layout, never behavior. The tool rearranges whitespace and line breaks; it does not rename variables, remove code or alter logic, so the script does exactly what it did before, just laid out clearly.

Because JSON is valid JavaScript syntax, you can also paste a JSON object or array and get it cleanly indented, which is handy when you have a blob of data rather than code.

It beautifies rather than minifies. Safe minification needs a full parser to rename and drop code without changing behavior, so this tool focuses on making code readable rather than smaller.