How does it tell a regex from a division sign?

By what comes before it, which is the same rule every JavaScript parser uses. A `/` after something that could end an expression — an identifier, a number, a closing bracket — is division. Anywhere else it opens a regular expression. That's what lets `a / b` and `text.replace(/a/g, "")` both survive intact.

Will beautifying change what the code does?

It shouldn't. Only whitespace outside strings is altered, and JavaScript's automatic semicolon insertion only ever adds semicolons at line ends where a statement is already complete. That said, this is a formatter rather than a parser, so run the result through your tests rather than deploying it on faith.

Does it handle TypeScript, JSX or minified React?

TypeScript and JSX will indent sensibly, because their brace structure is ordinary JavaScript. JSX with expressions in attributes is fine; deeply nested JSX won't be laid out the way Prettier would. For code you own, use Prettier — this is for reading code you didn't write.

JavaScript Beautifier

Take minified or badly formatted JavaScript and get indentation back. The hard part of doing this correctly is knowing what is code and what isn't: a brace inside a string, a slash that opens a regular expression rather than dividing, a template literal spanning five lines. Each of those is scanned and copied through untouched here, so the indentation follows the real block structure rather than whatever punctuation happened to appear.

Your text

Indent

Result

Nothing is uploaded — this tool runs inside your browser, so your files never leave your device.

Help us improve

Why use this tool

Indents by real brace and bracket depth, not by counting characters
Strings, template literals, regular expressions and comments are preserved exactly
Keeps `} else {` and `} catch {` together rather than splitting them
Runs in your browser — paste a whole production bundle if you want to read it

How it works

1Paste the JavaScript you want to read.
2Choose two spaces, four spaces or tabs.
3Copy the formatted code into your editor.

JavaScript Beautifier — frequently asked questions

You get the structure back, not the names. A minifier renames local variables to single letters and that is irreversible — no formatter can turn `t` back into `userAccountBalance`. If the site publishes a source map, that will give you the true original; without one, beautified code is the best available.

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