JS Beautifier

This little beautifier will reformat and reindent bookmarklets, ugly JavaScript, unpack scripts packed by Dean Edward’s popular packer, as well as deobfuscate scripts processed by javascriptobfuscator.com.

Usage

You can beautify javascript using JS Beautifier in your web browser, or on the command-line using node.js or python.

Web Browser

Open jsbeautifier.org. Options are available via the UI.

Python

To beautify using python:

$ pip install jsbeautifier
$ js-beautify file.js

Beautified output goes to stdout.

To use jsbeautifier as a library is simple:

import jsbeautifier
res = jsbeautifier.beautify('your javascript string')
res = jsbeautifier.beautify_file('some_file.js')

...or, to specify some options:

opts = jsbeautifier.default_options()
opts.indent_size = 2
res = jsbeautifier.beautify('some javascript', opts)

JavaScript

As an alternative to the Python script, you may install the NPM package js-beautify. When installed globally, it provides an executable js-beautify script. As with the Python script, the beautified result is sent to stdout unless otherwise configured.

$ npm -g install js-beautify
$ js-beautify foo.js

You can also use js-beautify as a node library (install locally, the npm default):

$ npm install js-beautify

var beautify = require('js-beautify').js_beautify,
    fs = require('fs');

fs.readFile('foo.js', 'utf8', function (err, data) {
    if (err) {
        throw err;
    }
    console.log(beautify(data, { indent_size: 2 }));
});

Options

These are the command-line flags for both Python and JS scripts:

CLI Options:
  -f, --file       Input file(s) (Pass '-' for stdin)
  -r, --replace    Write output in-place, replacing input
  -o, --outfile    Write output to file (default stdout)
  --config         Path to config file
  --type           [js|css|html] ["js"]
  -q, --quiet      Suppress logging to stdout
  -h, --help       Show this help
  -v, --version    Show the version

Beautifier Options:
  -s, --indent-size                 Indentation size [4]
  -c, --indent-char                 Indentation character [" "]
  -l, --indent-level                Initial indentation level [0]
  -t, --indent-with-tabs            Indent with tabs, overrides -s and -c
  -p, --preserve-newlines           Preserve line-breaks (--no-preserve-newlines disables)
  -m, --max-preserve-newlines       Number of line-breaks to be preserved in one chunk [10]
  -P, --space-in-paren              Add padding spaces within paren, ie. f( a, b )
  -j, --jslint-happy                Enable jslint-stricter mode
  -a, --space-after-anon-function   Add a space before an anonymous function's parens, ie. function ()
  -b, --brace-style                 [collapse|expand|end-expand|none] ["collapse"]
  -B, --break-chained-methods       Break chained method calls across subsequent lines
  -k, --keep-array-indentation      Preserve array indentation
  -x, --unescape-strings            Decode printable characters encoded in xNN notation
  -w, --wrap-line-length            Wrap lines at next opportunity after N characters [0]
  -X, --e4x                         Pass E4X xml literals through untouched
  -n, --end_with_newline            End output with newline
  --good-stuff                      Warm the cockles of Crockford's heart

These largely correspond to the underscored option keys for both library interfaces, which have these defaults:

{
    "indent_size": 4,
    "indent_char": " ",
    "indent_level": 0,
    "indent_with_tabs": false,
    "preserve_newlines": true,
    "max_preserve_newlines": 10,
    "jslint_happy": false,
    "space_after_anon_function": false,
    "brace_style": "collapse",
    "keep_array_indentation": false,
    "keep_function_indentation": false,
    "space_before_conditional": true,
    "break_chained_methods": false,
    "eval_code": false,
    "unescape_strings": false,
    "wrap_line_length": 0
}

In addition to CLI arguments, you may pass config to the JS executable via:

• any jsbeautify_-prefixed environment variables
• a JSON-formatted file indicated by the --config parameter
• a .jsbeautifyrc file containing JSON data at any level of the filesystem above $PWD

Configuration sources provided earlier in this stack will override later ones.

You might notice that the CLI options and defaults hash aren't 100% correlated. Historically, the Python and JS APIs have not been 100% identical. For example, space_before_conditional is currently JS-only, and not addressable from the CLI script. There are a few other additional cases keeping us from 100% API-compatibility. Patches welcome!

CSS & HTML

In addition to the js-beautify executable, css-beautify and html-beautify are also provided as an easy interface into those scripts. Alternatively, js-beautify --css or js-beautify --html will accomplish the same thing, respectively.

// Programmatic access
var beautify_js = require('js-beautify'); // also available under "js" export
var beautify_css = require('js-beautify').css;
var beautify_html = require('js-beautify').html;

// All methods accept two arguments, the string to be beautified, and an options object.

The CSS & HTML beautifiers are much simpler in scope, and possess far fewer options.

CSS Beautifier Options:
  -s, --indent-size                  Indentation size [4]
  -c, --indent-char                  Indentation character [" "]
  -L, --selector-separator-newline   Add a newline between multiple selectors
  -N, --newline-between-rules        Add a newline between CSS rules

HTML Beautifier Options:
  -I, --indent-inner-html            Indent <head> and <body> sections. Default is false.
  -s, --indent-size                  Indentation size [4]
  -c, --indent-char                  Indentation character [" "]
  -b, --brace-style                  [collapse|expand|end-expand|none] ["collapse"]
  -S, --indent-scripts               [keep|separate|normal] ["normal"]
  -w, --wrap-line-length             Maximum characters per line (0 disables) [250]
  -p, --preserve-newlines            Preserve existing line-breaks (--no-preserve-newlines disables)
  -m, --max-preserve-newlines        Maximum number of line-breaks to be preserved in one chunk [10]
  -U, --unformatted                  List of tags (defaults to inline) that should not be reformatted
  -n, --end_with_newline             End output with newline

License

You are free to use this in any way you want, in case you find this useful or working for you but you must keep the copyright notice and license. (MIT)

Credits

• Written by Einar Lielmanis, einar@jsbeautifier.org
• Python version flourished by Stefano Sanfilippo a.little.coder@gmail.com
• General maintenance and expansion by Liam Newman bitwiseman@gmail.com
• Command-line for node.js by Daniel Stockman daniel.stockman@gmail.com

Thanks also to Jason Diamond, Patrick Hof, Nochum Sossonko, Andreas Schneider, Dave Vasilevsky, Vital Batmanov, Ron Baldwin, Gabriel Harrison, Chris J. Shull, Mathias Bynens, Vittorio Gambaletta and others.

js-beautify@1.5.3