One of the things that has always annoyed me in regards to Firefox’s private browsing mode was the fact that the browser did close the active session before switching to that mode. And while Firefox offers to save the active session, that is the open tabs and other session related information, it is nowhere near as comfortable as a solution that would spawn a new private browsing window without affecting the active session.
Google Chrome and the Opera web browser handle the private browsing mode this way for instance. When you start the incognito mode in Chrome for instance, you will notice that it spawns in a new window without affecting the old regular browser window.
Private Browsing Windows for the Firefox web browser bypasses the restriction in Firefox. Since it is not possible to override the feature directly to open the private browsing mode in a new window, developer Sören Hentzschel came up with the next best possibility: Use a different Firefox profile to load the private browsing mode window. This way, it is possible to keep the original Firefox window and have the private browsing window appear in a new window at the same time.
The extension will automatically use a profile that is labelled as private. It will otherwise launch the built-in Firefox profile manager to provide the user with a selection menu (and an option to create a new profile if only one exists). This profile is then used to load the private browsing window in Firefox. The profile manager pops up every time, unless you change the name of a profile to private.
Private Browsing Windows adds an icon into Firefox’s add-on bar that triggers the extension’s functionality.
Users who try the extension need to keep in mind that they need to close the browser windows in the correct order, to avoid the loading of the wrong profile on the next start.
The extension can be useful for Firefox users who work in the private browsing mode from time to time, and wish that there was a way to keep the regular browser window open when they do.