JavaScript Formatter and Minifier

Paste a script, choose a mode and copy the result. The output updates as you type.

1. Paste JavaScript into the Input box, or press Paste. A minified bundle, a function copied from dev tools and a whole module all work, and Try it loads a short example.
2. Set Mode to Beautify to re-indent the code, or to Safe minify (keeps line breaks) to remove comments and indentation.
3. Choose the Indent: 2 spaces, 4 spaces or Tab. It only affects Beautify.
4. Read the status line. It says "Beautified", or for Safe minify it shows the length before and after.
5. Press Copy or Download .txt, then rename the download to .js. Use as input moves the result back into the input box.

Beautify uses the js-beautify library in your browser. Nothing is uploaded, and the tool never runs the code it formats, so pasting an unknown script here is safe even when running it would not be.

Beautify rebuilds indentation and spacing from the structure of the code. The example function a(){return 1} becomes three lines with the body indented. Each statement gets its own line, spaces are normalised around operators and commas, and the opening brace stays on the same line as the function, if or for that owns it. Object literals and destructuring patterns are spread over several lines, so const {a,b} = x is expanded rather than kept compact, while a short array of plain values such as [1, 2, 3] stays on one line.

Modern syntax is handled: arrow functions, classes with private fields, template literals, spread, async and await, optional chaining and modules. Comments are kept. Semicolons are neither added nor removed, and names are not restored, so a minified a or b stays as it is, though the control flow becomes readable. The tool does not check syntax: broken code is simply laid out as far as the beautifier can follow it, with no error message. JSX and TypeScript are not plain JavaScript and come out mangled, with spaces inserted inside tags and angle brackets.

The mode is called safe because it keeps every line break. JavaScript inserts semicolons automatically at some line ends, so a return followed by a new line returns nothing, and a line that starts with a bracket continues the line above. Joining lines without a full parser could change behaviour, so this mode removes comments, trims each line, deletes blank lines and removes spaces that are not needed between tokens. The three-line function function add(a, b) with return a + b; inside comes out as function add(a,b){, return a+b; and }, and the status line reports 38 characters reduced to 32.

It is a character scanner, not a parser, so look closely at the output if your code contains:

• Two plus or two minus signs separated by a space, as in a + +b or a - -b. The spaces are removed, giving a++b and a--b, which mean something different.
• A regular expression literal after a keyword such as return. return /a +b/ loses its space and becomes a different pattern.
• Multi-line template literals. The indentation of continuation lines is trimmed, changing the text.

For a production build use Terser, esbuild or SWC through your bundler. They parse the program, rename local variables, remove dead code and produce source maps. Use this mode for snippets and bookmarklets.

Readable code is the starting point for every other task, and a formatter is the quickest way to get there.

• Unminify a vendor script or bundle to find out where it posts data or why it throws.
• Tidy code pasted from a chat message, PDF or forum answer that lost its indentation.
• Normalise a file before comparing versions, so the diff checker shows logic changes rather than whitespace.
• Read a bookmarklet or javascript: link before you run it.
• Turn a long one-liner from the console into a function you can keep.

When the input is data rather than code, such as an API response or a configuration object, the JSON formatter also validates it, which this tool does not. If a pattern in your script misbehaves, the regex tester lets you debug it on sample text, and the HTML formatter will tidy the page that loads the script.