Gathering detailed insights and metrics for js-beautify
Gathering detailed insights and metrics for js-beautify
Installations
npm install js-beautifyDeveloper Guide
BETA
Typescript
No
Module System
CommonJS
Min. Node Version
>=14
Node Version
18.20.7
NPM Version
10.9.2
Releases
27
Languages
7
JavaScript
HTML
Python
Mustache
Shell
Makefile
CSS
JavaScript (42.74%)
HTML (35.94%)
Python (15.51%)
Mustache (2.68%)
Shell (2.63%)
Makefile (0.3%)
CSS (0.2%)
Developer
Download Statistics
Total Downloads
0
Last Day
0
Last Week
0
Last Month
0
Last Year
0
GitHub Statistics
MIT License
8,805 Stars
3,281 Commits
1,398 Forks
209 Watchers
18 Branches
215 Contributors
Updated on Jul 15, 2025
Maintainers
2
Package Meta Information
Latest Version
1.15.4
Package Id
js-beautify@1.15.4
Unpacked Size
958.77 kB
Size
191.74 kB
File Count
46
NPM Version
10.9.2
Node Version
18.20.7
Published on
Feb 27, 2025
Total Downloads
Cumulative downloads
Total Downloads
NaN
Last Day
0%
NaN
Compared to previous day
Last Week
0%
NaN
Compared to previous week
Last Month
0%
NaN
Compared to previous month
Last Year
0%
NaN
Compared to previous year
Weekly Downloads
Monthly Downloads
Yearly Downloads
![NPM stats](https://nodei.co/npm/js-beautify.svg?downloadRank=true&downloads=true"/)
This little beautifier will reformat and re-indent bookmarklets, ugly JavaScript, unpack scripts packed by Dean Edward’s popular packer, as well as partly deobfuscate scripts processed by the npm package javascript-obfuscator.
Open beautifier.io to try it out. Options are available via the UI.
Contributors Needed
I'm putting this front and center above because existing owners have very limited time to work on this project currently. This is a popular project and widely used but it desperately needs contributors who have time to commit to fixing both customer facing bugs and underlying problems with the internal design and implementation.
If you are interested, please take a look at the CONTRIBUTING.md then fix an issue marked with the "Good first issue" label and submit a PR. Repeat as often as possible. Thanks!
Installation
You can install the beautifier for Node.js or Python.
Node.js JavaScript
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.
1$ npm -g install js-beautify 2$ js-beautify foo.js
You can also use js-beautify as a node library (install locally, the npm default):
1$ npm install js-beautify
Node.js JavaScript (vNext)
The above install the latest stable release. To install beta or RC versions:
1$ npm install js-beautify@next
Web Library
The beautifier can be added on your page as web library.
JS Beautifier is hosted on two CDN services: cdnjs and rawgit.
To pull the latest version from one of these services include one set of the script tags below in your document:
1<script src="https://cdnjs.cloudflare.com/ajax/libs/js-beautify/1.15.4/beautify.js"></script> 2<script src="https://cdnjs.cloudflare.com/ajax/libs/js-beautify/1.15.4/beautify-css.js"></script> 3<script src="https://cdnjs.cloudflare.com/ajax/libs/js-beautify/1.15.4/beautify-html.js"></script> 4 5<script src="https://cdnjs.cloudflare.com/ajax/libs/js-beautify/1.15.4/beautify.min.js"></script> 6<script src="https://cdnjs.cloudflare.com/ajax/libs/js-beautify/1.15.4/beautify-css.min.js"></script> 7<script src="https://cdnjs.cloudflare.com/ajax/libs/js-beautify/1.15.4/beautify-html.min.js"></script>
Example usage of a JS tag in html:
1<!DOCTYPE html> 2<html lang="en"> 3 <body> 4 5. . . 6 7 <script src="https://cdnjs.cloudflare.com/ajax/libs/js-beautify/1.15.4/beautify.min.js"></script> 8 <script src="script.js"></script> 9 </body> 10</html>
Older versions are available by changing the version number.
Disclaimer: These are free services, so there are no uptime or support guarantees.
Python
To install the Python version of the beautifier:
1$ pip install jsbeautifier
Unlike the JavaScript version, the Python version can only reformat JavaScript. It does not work against HTML or CSS files, but you can install css-beautify for CSS:
1$ pip install cssbeautifier
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 beautifier.io. Options are available via the UI.
Web Library
After you embed the <script> tags in your html file, they expose three functions: js_beautify, css_beautify, and html_beautify
Example usage of beautifying a json string:
1const options = { indent_size: 2, space_in_empty_paren: true } 2 3const dataObj = {completed: false,id: 1,title: "delectus aut autem",userId: 1,} 4 5const dataJson = JSON.stringify(dataObj) 6 7js_beautify(dataJson, options) 8 9/* OUTPUT 10{ 11 "completed": false, 12 "id": 1, 13 "title": "delectus aut autem", 14 "userId": 1, 15} 16*/
Node.js JavaScript
When installed globally, the beautifier provides an executable js-beautify script. The beautified result is sent to stdout unless otherwise configured.
1$ js-beautify foo.js
To use js-beautify as a node library (after install locally), import and call the appropriate beautifier method for JavaScript (JS), CSS, or HTML. All three method signatures are beautify(code, options). code is the string of code to be beautified. options is an object with the settings you would like used to beautify the code.
The configuration option names are the same as the CLI names but with underscores instead of dashes. For example, --indent-size 2 --space-in-empty-paren would be { indent_size: 2, space_in_empty_paren: true }.
1var beautify = require('js-beautify/js').js, 2 fs = require('fs'); 3 4fs.readFile('foo.js', 'utf8', function (err, data) { 5 if (err) { 6 throw err; 7 } 8 console.log(beautify(data, { indent_size: 2, space_in_empty_paren: true })); 9});
If you are using ESM Imports, you can import js-beautify like this:
1// 'beautify' can be any name here. 2import beautify from 'js-beautify'; 3 4beautify.js(data, options); 5beautify.html(data, options); 6beautify.css(data, options);
Python
After installing, to beautify using Python:
1$ js-beautify file.js
Beautified output goes to stdout by default.
To use jsbeautifier as a library is simple:
1import jsbeautifier 2res = jsbeautifier.beautify('your JavaScript string') 3res = jsbeautifier.beautify_file('some_file.js')
...or, to specify some options:
1opts = jsbeautifier.default_options() 2opts.indent_size = 2 3opts.space_in_empty_paren = True 4res = jsbeautifier.beautify('some JavaScript', opts)
The configuration option names are the same as the CLI names but with underscores instead of dashes. The example above would be set on the command-line as --indent-size 2 --space-in-empty-paren.
Options
These are the command-line flags for both Python and JS scripts:
1CLI Options: 2 -f, --file Input file(s) (Pass '-' for stdin) 3 -r, --replace Write output in-place, replacing input 4 -o, --outfile Write output to file (default stdout) 5 --config Path to config file 6 --type [js|css|html] ["js"] Select beautifier type (NOTE: Does *not* filter files, only defines which beautifier type to run) 7 -q, --quiet Suppress logging to stdout 8 -h, --help Show this help 9 -v, --version Show the version 10 11Beautifier Options: 12 -s, --indent-size Indentation size [4] 13 -c, --indent-char Indentation character [" "] 14 -t, --indent-with-tabs Indent with tabs, overrides -s and -c 15 -e, --eol Character(s) to use as line terminators. 16 [first newline in file, otherwise "\n] 17 -n, --end-with-newline End output with newline 18 --editorconfig Use EditorConfig to set up the options 19 -l, --indent-level Initial indentation level [0] 20 -p, --preserve-newlines Preserve line-breaks (--no-preserve-newlines disables) 21 -m, --max-preserve-newlines Number of line-breaks to be preserved in one chunk [10] 22 -P, --space-in-paren Add padding spaces within paren, ie. f( a, b ) 23 -E, --space-in-empty-paren Add a single space inside empty paren, ie. f( ) 24 -j, --jslint-happy Enable jslint-stricter mode 25 -a, --space-after-anon-function Add a space before an anonymous function's parens, ie. function () 26 --space-after-named-function Add a space before a named function's parens, i.e. function example () 27 -b, --brace-style [collapse|expand|end-expand|none][,preserve-inline] [collapse,preserve-inline] 28 -u, --unindent-chained-methods Don't indent chained method calls 29 -B, --break-chained-methods Break chained method calls across subsequent lines 30 -k, --keep-array-indentation Preserve array indentation 31 -x, --unescape-strings Decode printable characters encoded in xNN notation 32 -w, --wrap-line-length Wrap lines that exceed N characters [0] 33 -X, --e4x Pass E4X xml literals through untouched 34 --good-stuff Warm the cockles of Crockford's heart 35 -C, --comma-first Put commas at the beginning of new line instead of end 36 -O, --operator-position Set operator position (before-newline|after-newline|preserve-newline) [before-newline] 37 --indent-empty-lines Keep indentation on empty lines 38 --templating List of templating languages (auto,django,erb,handlebars,php,smarty,angular) ["auto"] auto = none in JavaScript, all in HTML
Which correspond to the underscored option keys for both library interfaces
defaults per CLI options
1{ 2 "indent_size": 4, 3 "indent_char": " ", 4 "indent_with_tabs": false, 5 "editorconfig": false, 6 "eol": "\n", 7 "end_with_newline": false, 8 "indent_level": 0, 9 "preserve_newlines": true, 10 "max_preserve_newlines": 10, 11 "space_in_paren": false, 12 "space_in_empty_paren": false, 13 "jslint_happy": false, 14 "space_after_anon_function": false, 15 "space_after_named_function": false, 16 "brace_style": "collapse", 17 "unindent_chained_methods": false, 18 "break_chained_methods": false, 19 "keep_array_indentation": false, 20 "unescape_strings": false, 21 "wrap_line_length": 0, 22 "e4x": false, 23 "comma_first": false, 24 "operator_position": "before-newline", 25 "indent_empty_lines": false, 26 "templating": ["auto"] 27}
defaults not exposed in the cli
1{ 2 "eval_code": false, 3 "space_before_conditional": true 4}
Notice not all defaults are exposed via the CLI. Historically, the Python and JS APIs have not been 100% identical. There are still a few other additional cases keeping us from 100% API-compatibility.
Loading settings from environment or .jsbeautifyrc (JavaScript-Only)
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--configparameter - a
.jsbeautifyrcfile containingJSONdata at any level of the filesystem above$PWD
Configuration sources provided earlier in this stack will override later ones.
Setting inheritance and Language-specific overrides
The settings are a shallow tree whose values are inherited for all languages, but can be overridden. This works for settings passed directly to the API in either implementation. In the JavaScript implementation, settings loaded from a config file, such as .jsbeautifyrc, can also use inheritance/overriding.
Below is an example configuration tree showing all the supported locations
for language override nodes. We'll use indent_size to discuss how this configuration would behave, but any number of settings can be inherited or overridden:
1{ 2 "indent_size": 4, 3 "html": { 4 "end_with_newline": true, 5 "js": { 6 "indent_size": 2 7 }, 8 "css": { 9 "indent_size": 2 10 } 11 }, 12 "css": { 13 "indent_size": 1 14 }, 15 "js": { 16 "preserve-newlines": true 17 } 18}
Using the above example would have the following result:
- HTML files
- Inherit
indent_sizeof 4 spaces from the top-level setting. - The files would also end with a newline.
- JavaScript and CSS inside HTML
- Inherit the HTML
end_with_newlinesetting. - Override their indentation to 2 spaces.
- Inherit the HTML
- Inherit
- CSS files
- Override the top-level setting to an
indent_sizeof 1 space.
- Override the top-level setting to an
- JavaScript files
- Inherit
indent_sizeof 4 spaces from the top-level setting. - Set
preserve-newlinestotrue.
- Inherit
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.
1// Programmatic access 2var beautify_js = require('js-beautify'); // also available under "js" export 3var beautify_css = require('js-beautify').css; 4var beautify_html = require('js-beautify').html; 5 6// 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.
1CSS Beautifier Options: 2 -s, --indent-size Indentation size [4] 3 -c, --indent-char Indentation character [" "] 4 -t, --indent-with-tabs Indent with tabs, overrides -s and -c 5 -e, --eol Character(s) to use as line terminators. (default newline - "\\n") 6 -n, --end-with-newline End output with newline 7 -b, --brace-style [collapse|expand] ["collapse"] 8 -L, --selector-separator-newline Add a newline between multiple selectors 9 -N, --newline-between-rules Add a newline between CSS rules 10 --indent-empty-lines Keep indentation on empty lines 11 12HTML Beautifier Options: 13 -s, --indent-size Indentation size [4] 14 -c, --indent-char Indentation character [" "] 15 -t, --indent-with-tabs Indent with tabs, overrides -s and -c 16 -e, --eol Character(s) to use as line terminators. (default newline - "\\n") 17 -n, --end-with-newline End output with newline 18 -p, --preserve-newlines Preserve existing line-breaks (--no-preserve-newlines disables) 19 -m, --max-preserve-newlines Maximum number of line-breaks to be preserved in one chunk [10] 20 -I, --indent-inner-html Indent <head> and <body> sections. Default is false. 21 -b, --brace-style [collapse-preserve-inline|collapse|expand|end-expand|none] ["collapse"] 22 -S, --indent-scripts [keep|separate|normal] ["normal"] 23 -w, --wrap-line-length Maximum characters per line (0 disables) [250] 24 -A, --wrap-attributes Wrap attributes to new lines [auto|force|force-aligned|force-expand-multiline|aligned-multiple|preserve|preserve-aligned] ["auto"] 25 -M, --wrap-attributes-min-attrs Minimum number of html tag attributes for force wrap attribute options [2] 26 -i, --wrap-attributes-indent-size Indent wrapped attributes to after N characters [indent-size] (ignored if wrap-attributes is "aligned") 27 -d, --inline List of tags to be considered inline tags 28 --inline_custom_elements Inline custom elements [true] 29 -U, --unformatted List of tags (defaults to inline) that should not be reformatted 30 -T, --content_unformatted List of tags (defaults to pre) whose content should not be reformatted 31 -E, --extra_liners List of tags (defaults to [head,body,/html] that should have an extra newline before them. 32 --editorconfig Use EditorConfig to set up the options 33 --indent_scripts Sets indent level inside script tags ("normal", "keep", "separate") 34 --unformatted_content_delimiter Keep text content together between this string [""] 35 --indent-empty-lines Keep indentation on empty lines 36 --templating List of templating languages (auto,none,django,erb,handlebars,php,smarty,angular) ["auto"] auto = none in JavaScript, all in html
Directives
Directives let you control the behavior of the Beautifier from within your source files. Directives are placed in comments inside the file. Directives are in the format /* beautify {name}:{value} */ in CSS and JavaScript. In HTML they are formatted as <!-- beautify {name}:{value} -->.
Ignore directive
The ignore directive makes the beautifier completely ignore part of a file, treating it as literal text that is not parsed.
The input below will remain unchanged after beautification:
1// Use ignore when the content is not parsable in the current language, JavaScript in this case. 2var a = 1; 3/* beautify ignore:start */ 4 {This is some strange{template language{using open-braces? 5/* beautify ignore:end */
Preserve directive
NOTE: this directive only works in HTML and JavaScript, not CSS.
The preserve directive makes the Beautifier parse and then keep the existing formatting of a section of code.
The input below will remain unchanged after beautification:
1// Use preserve when the content is valid syntax in the current language, JavaScript in this case. 2// This will parse the code and preserve the existing formatting. 3/* beautify preserve:start */ 4{ 5 browserName: 'internet explorer', 6 platform: 'Windows 7', 7 version: '8' 8} 9/* beautify preserve:end */
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
- Created by Einar Lielmanis, einar@beautifier.io
- Python version flourished by Stefano Sanfilippo a.little.coder@gmail.com
- Command-line for node.js by Daniel Stockman daniel.stockman@gmail.com
- Maintained and expanded by Liam Newman bitwiseman@beautifier.io
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.
(README.md: js-beautify@1.15.4)
No vulnerabilities found.
No security vulnerabilities found.