Extensions (also known as add-ons) are small programs you can install to add features to Firefox. Some extensions can take control of the home page (what you see when you start Firefox, open a new window, or click the home icon in the toolbar) or the New Tab page (what you see when you open a new tab). If this happens, Firefox will ask you when you open it for the first time if that change is okay.

View and disable the extension

1. In the Menu bar at the top of the screen, click Firefox and then select Preferences or Settings, depending on your macOS version.Click the menu button and select Settings.
2. Click Home.
3. Under New Windows and Tabs, it will indicate which extension has changed your home page or New Tab page.

   

4. Click Disable Extension to prevent the extension from changing your home or New Tab page again. The page will change back to what you had previously set. To change your home page again, see How to set the home page.

Remove the extension

1. Click the menu button , click Add-ons and themes and select Extensions.
2. Under Manage Your Extensions find the extension you want to remove.
3. On the right side of the extension click the menu (three dots) and select Remove.