You don't have to do anything special to install apps on different platforms. All the information you need to provide, such as the app name, is contained in the app manifest. Here are some platform-specific details about how apps are installed on each platform. These details assume that Firefox has been installed on the platform.

Firefox OS (Boot to Gecko)

Gaia (the Firefox OS user interface) includes a marketplace link on the second homepage, and apps can be installed in this way. Default apps included with Gaia are stored in the Gecko profile on the device as an offline cache of the Web app at /data/local/OfflineCache/*.

If you want to browse this folder to look at the contents, you can do so using the adb tool:

$ adb shell ls -la /data/local/OfflineCache/

All other installed apps are stored in the DOM Registry component (you can find this file at /data/local/webapps). If they use appcache, the appcache will be populated at install time.

Desktop platforms

The sections that follow explain where the files for installable web apps are located when installed on desktop platforms. But this doesn't tell the whole story. Since Firefox 29, Firefox Desktop has had a component called Web Runtime for Desktop. This enables free Marketplace apps to be installed by Firefox Desktop into a user's Windows, Mac, or Linux computer. Once installed on a desktop computer, these apps run similarly to any other desktop app, in terms of installation, etc.

To find out more, read Open Web Apps for Desktop.


The following are created upon installation. All of these will be removed by the uninstaller (find it in the Windows Control Panel).

  • Shortcut on the current user's desktop.
  • Shortcut in Start menu > Programs for the current user.
  • Registry entries to make the app appear in the Control Panel's "uninstall a program" menu.
  • Folders for the app under %APPDATA%\scheme;domain[;port]
    • Where scheme is http or https, domain is the app's domain name, and port is a port number, used only if the default port number is not used.
    • Example folder name: C:\Users\myuser\AppData\Roaming\https;;115
    • The folders contain a stub executable (exe), configuration files, and an uninstaller.

When launched, each app has its own window with the following attributes:

  • A native menu bar (currently with File and Edit menus).
  • The title of the window is the name of the app.
  • System menu icon (in the upper left corner of the window) is specified by the app manifest.
  • The displayed Taskbar icon is also specified by the app manifest.

Each app runs in a separate process, and the app appears under its own name on the Applications tab of Task Manager. The executable name of the app (for example, "Mozilla QA WebRT Tester.exe") is the app name with illegal Windows filename characters removed.

Each app has its own profile with separate preferences, cookies, history, certificate authority settings, proxy settings, etc. Upon first run, profile data is created in the directory mentioned above, and in an equivalent directory in %LOCALAPPDATA%. Profile data is not removed by the uninstaller.

Mac OS X

Apps are installed into /Applications.

Opening the app launches the app in its own window minus the browser window frame. Apps execute using the Firefox binary. Each app runs in a separate process. Each app has its own profile, with separate preferences, cookies, certificate authority settings, proxy settings, etc.


Apps are installed directly in the $HOME of the user. For example if an app comes from it will get installed in $HOME/.http\;

The installation creates also a new entry in the desktop menu according to the Freedesktop specifications. It works on every desktop following the Freedesktop specifications such as KDE and Gnome.

The new entry is located in the $HOME/.local/share/applications/ directory of the user.

In KDE the new entry appears in an "Found Objects" menu group of the "Application" menu.

In Gnome the new entry appears in an "Others" menu group of the "Application" menu, see the screenshot.


If you install a web app from outside of the Firefox Marketplace, the installation creates an icon on the home screen, but the app will not be added to the application list that is available from the Settings menu on the Android device.

However, the Marketplace has a tool available called the APK factory that will generate an APK version of your app (the same, but packaged in a Java wrapper with some API code for accessing native APIs), as long as you select Android as a distribution target when uploading your app. When such apps are installed on an Android device, they are passed the APK version of the app, which has all the installation advantages of regular Android apps, but can still be run via the Web Runtime for Android contained within Firefox for Android.

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Last updated by: chrisdavidmills,