JavaScript Beautifier

The JavaScript Beautifier re indents and tidies minified or hand edited JavaScript so it is readable again, without changing what the code does. Reformatting only affects whitespace, so the tokens and the meaning stay the same, which means you can safely run it before you edit and then clean it up after if you want. It is the fastest way to understand a bundled file you received, to line up a diff, or to make a log of code you can actually read. The tool works locally in your browser, so the code you format is never uploaded. Minified JavaScript is produced by stripping whitespace and shortening names, which makes it small over the wire and unreadable to a person. Reindenting it restores the visual structure without altering a single token, so the meaning of the code, its order of execution, and its behaviour are all unchanged. That distinction is the reason the operation is safe to apply casually: it is a formatting transform, and if you format a file, work on it, and then re-minify, the result is functionally the same code. The practical value comes up constantly when you are dealing with code you did not write and cannot easily rebuild, such as a bundle shipped by a third party, a script pasted out of a browser debugger, or a file recovered from somewhere without its source. Having it indented makes it possible to find the function you care about, set a breakpoint in the right place, and produce a readable excerpt for a bug report. The work happens in the browser, so proprietary code you are diagnosing never leaves your machine.

📘 Related guide: Beautify minified JavaScript in the browser →