App/Xtn/Browser/XOWA viewer

From XOWA: the free, open-source, offline wiki application

The XOWA viewer is an add-on for the Firefox browser. It allows Firefox to show XOWA pages by using an "xowa:" protocol (instead of "http:"). For example, navigating to will retrieve the HTML from XOWA but show it in Firefox.


Considerable thanks goes to treck for proposing and developing the XOWA viewer addon.


Pale Moon

As of Firefox version 43, unsigned addons are no longer supported. See The XOWA Firefox Addon should be signed in the future, but in the meantime, you can use the open-source alternative Pale Moon as a substitute:


Note that you will need a version earlier than 43, or a developer / nightly build

  • Using File -> Open File, open the XPI from /xowa/bin/any/firefox/xowa_viewer/default/xowa_viewer.xpi
  • Set the jar location for "extensions.xowa_viewer.xowa_app" in about:config. See Config below


The Add-on installs an XOWA toolbar button called "XOWA Home". Users can enable it by doing the following:

  • Right-click on any toolbar in Firefox
  • Choose "Customize"
  • Find the "XOWA Home" button and drag it to the toolbar

Features and Limitations

The XOWA viewer is a work in progress. XOWA needs to make changes to communicate with Firefox over TCP (right now it communicates directly with the embedded browser)

The following is a high-level list of supported features:

  • On the Firefox Menu Bar, Tools -> XOWA home will navigate to home/wiki/Main_Page
  • Navigate to a url by typing in the url with an xowa protocol. For example,
  • Click on any link, and it will open the page in Firefox
  • The following javascript libraries will work:
    • MathJax
    • Reference tooltips
    • Sortable / collapsible
    • Timeline
    • Search-suggest
    • Wikidata JSON formatter
  • Close the browser and the XOWA server will shut down.

The following is a high-level list of current limitations (Note that these will be addressed in future builds):

  • xowa-cmd links will not work. This includes links to Read, Edit, View HTML, Exit, and Bookmark this page. This requires support for the "xowa-cmd:" protocol
  • The following javascript related items will not work. They require support for calling Javascript in Firefox from XOWA.
    • Options pages
    • Wiki import


The addon has several options that can be configured.

  • Navigate to about:config
  • Search for "extensions.xowa"
  • The most important item is "extensions.xowa_viewer.xowa_app". This needs to point to your local xowa.jar.
    • On Windows, it may be C:\xowa\xowa_windows.jar
    • On Linux, it may be /home/user/your_user_name/xowa/xowa_linux.jar
    • On Mac OS X, it may be /Users/your_user_name/xowa/xowa_macosx.jar

Developer: Source code

The source code is available under the Mozilla Public License at gitub.

It is also contained in the Addon itself. You can unzip the .xpi and examine any of the underlying files. The code is in javascript and there are no binary dependencies.

Developer: Install

  • Go to and choose Download Zip
  • Extract the zip file
  • Navigate to the extension directory and add all its files / directories (chrome, content, install.rdf, etc.) to a new zip file called "". (You can use 7-zip or your favorite compression program)
  • Rename file to xowa_viewer.xpi
  • Open the xowa_viewer.xpi in Firefox



Getting started