This article explains how to set which extensions are allowed to run in Private Browsing windows.

Extensions in private windows

In previous Firefox versions, any extensions you installed would run in private and non-private browsing windows by default. This could be problematic if an extension accessed information you would rather keep private while browsing in a private window.

Starting in Firefox version 67, you will be able to decide which extensions will run while you are in private browsing. Additionally, an extension will no longer automatically be able to work in private browsing; you must grant it permission, either when you install the extension or later, through the extension’s settings.

If you do not give an extension permission to work in private browsing, it should still work normally in non-private browsing, unless the extension explicitly uses features that require private browsing access (like opening new tabs in a private window).

Granting permission on installation

When you install a new extension, you will see a prompt asking if you would like this extension to work in private windows.

If you would like the extension to work in private browsing, click on the box next to Allow this extension to run in Private Windows to add a check mark and then click on the Okay, Got It bar.

If you do not want the extension to have access to your data in private browsing windows, leave the box unchecked.

Enabling or disabling extensions in private windows

1. Click the menu button The image "Fx57menu" does not exist., click Add-ons and Themes Add-ons and select Extensions.
2. Click on the card of the extension you would like to manage.
   • This will open a panel where you can manage extension settings.

Underneath the description of the extension, you will see extension settings. Next to Run in Private Windows, select Allow to enable the extension to work in private browsing or select Don’t Allow to disable it in private browsing. Once you have made your selection, you can exit the Add-ons Manager.