Skip to content


Subversion checkout URL

You can clone with HTTPS or Subversion.

Download ZIP
Compare code instead of text.
JavaScript HTML Other
branch: master

Try it online at

Pretty Diff logo Pretty Diff

Gitter npm version Dependency Status

NPM stats


Language aware code comparison tool for several web based languages. It also beautifies, minifies, and a few other things.

Benefits - see overview page for more details

Run with Node.js / io.js / CommonJS / RequireJS

Node.js and io.js support is provided by api/node-local.js. This file can execute in the following modes:

  • auto - Determine if the resource is text, a file, or a directory and process as such (except that directories are processed with the subdirectory option)
  • screen - code input is on the command line and output is to the command line
  • filescreen - code input is in a file and the output is to the command line
  • file - the input and the output reside in files
  • directory - everything in a directory is processed into a specified output directory except ".", "..", and subdirectories
  • subdirectory - process the entire directory tree

Execute in the context of a NodeJS application

First install the prettydiff package locally

npm install prettydiff

Add this code to your application

var prettydiff = require("prettydiff"),
    args       = {
        source: "asdf",
        diff  : "asdd",
        lang  : "text"
    output     = prettydiff.api(args);

Execute from the command line

First install the prettydiff package globally

npm install prettydiff -g

Run in windows

prettydiff source:"c:\myDirectory" readmethod:"subdirectory" diff:"c:\myOtherDirectory"

Run in Linux and OSX

prettydiff source:"myDirectory" mode:"beautify" readmethod:"subdirectory" output:"path/to/outputDirectory"

To see a man page provide no arguments or these: help, man, manual

prettydiff help
prettydiff man

To see only the version number supply only v or version as an argument:

prettydiff v
prettydiff version

Run in a web browser with api/dom.js

Please feel free to use file to supplement dom.js. Otherwise, dom.js requires supplemental assistance to map DOM nodes from an HTML source. dom.js is fault tolerant so nodes mapped to the supplied don't need to be supported from custom HTML.

To run Pretty Diff using dom.js include the following two script tags and bind the pd.recycle() function to the executing event. Please refer to for an HTML example and documentation.xhtml for option and execution information.

<script type="application/javascript" src="prettydiff.js"></script>
<script type="application/javascript" src="api/dom.js"></script>

Run on Windows command line with WSH

Create a WSH script file using XML syntax and with a file extension of "WSF". This file must have a tag for each supported argument, must be capable of reading from a file, and retrieving dependencies.

Pretty Diff would be executed using the following on CLI:

cscript prettydiff.wsf
cscript prettydiff.wsf /source:"myFile.xml" /mode:"beautify"

Execute with vanilla JS

var args   = {
        source: "asdf",
        diff  : "asdd",
        lang  : "text"
    output = prettydiff(args);



@documentation - English:

@licstart The following is the entire license notice for Pretty Diff.

This code may not be used or redistributed unless the following conditions are met:

  • Prettydiff created by Austin Cheney originally on 3 Mar 2009.
  • The use of diffview.js and prettydiff.js must contain the following copyright: Copyright (c) 2007, Snowtide Informatics Systems, Inc. All rights reserved.
    • Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer.
    • Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution.
    • Neither the name of the Snowtide Informatics Systems nor the names of its contributors may be used to endorse or promote products derived from this software without specific prior written permission.
    • used as diffview function
  • CodeMirror Copyright (C) 2013 by Marijn Haverbeke and others - MIT License
  • The code mentioned above has significantly expanded documentation in each of the respective function's external JS file as linked from the documentation page:
  • In addition to the previously stated requirements any use of any component, aside from directly using the full files in their entirety, must restate the license mentioned at the top of each concerned file.

    If each and all these conditions are met use, extension, alteration, and redistribution of Pretty Diff and its required assets is unlimited and free without author permission.

    @licend The above is the entire license notice for Pretty Diff.


Something went wrong with that request. Please try again.