Mozilla Firefox is one of the most popular web browsers out there. It was one of the first feature-rich browsers with a focus on privacy and security. Moreover, no matter which website you access, it offers amazing speed and a pleasant user experience. One of the key features of the Firefox browser is the ability to add extensions. These days most modern browsers accept add-ons and extensions but Firefox is one of the first browsers that accepted add-ons in both mobile and desktop platforms. It has a decadent addon store where all addons are reviewed by a team of reviewers. In general, all addons are working in normal browsing mode, but if you want to work with an addon in private browsing mode please read this blog post. The reason why addons are not enabled in private browsing mode by default is the privacy and security nature of private browsing where it is designed to be isolated from almost all plugins.

As mentioned above, with private mode, the browser has to keep all your history private. Therefore, when you use private browsing mode, Firefox disables extensions to prevent data from getting leaked (or seen by the extensions). If you want to use a trusted extension when browsing privately, you need to manually allow it from the settings page. In this post, we share all the information that you need to know to be able to use extensions in private mode.

Steps to Enable a Firefox Extension

  • First please open the Firefox browser.
  • Then, select the Firefox menu button (top-right corner) from any of the open windows. For those of you that do not know what the menu button looks like, it comprises three horizontal lines.
  • Choose the “Add-ons and themes” item from the menu.
  • Then, a new tab would open the Add-ons Manager. It would show you a list of the Firefox extensions which you have already installed on your browser.
  • Now, what you need to do is scroll through the extensions and find the one that you want to activate while using Private mode.
  • Once you have identified the desired Firefox extension, you just have to click on the whole item as a button to open the detailed view.
  • Find the item that shows “Run in Private Windows” and then mark the Allow checkbox (default is Don’t Allow).

As the above steps are straightforward and you should have no trouble following them if you have the latest Firefox browser (for old browsers the above steps might be slightly different but the overall procedure is the same). Keep in mind that each extension that you enable would be able to access your browsing data even though you would be browsing privately. This means that the extension would store the data and might share it with third-party servers. Therefore it is a good practice to pay attention to the extensions functionality and permissions list before enabling the private browsing mode.

If there are any other extensions that you want to enable, you can simply follow the above steps. When you are done, you can just have to close the tab for Add-Ons Manager (all changes are saved automatically). Now, each private window that you open in Firefox would enable the selected extension. To turn off this feature, please follow the above steps and remove the private browsing permission (click on the Don’t Allow checkbox) for desired extensions.


After reading this post, you will be able to use desired Firefox extensions in private browsing mode that were previously turned off. This blog post is for the Firefox browser only but, is useful to mention that almost all modern browsers have this feature with a different procedure. Therefore, by reading this post you may be able to enable this feature in other browsers and use extensions in private mode.