In the drop-down menu next to Firefox will, choose Use custom settings for history.Select the Privacy & Security panel and go to the History section. Click the menu button and select Settings. Click the menu button and select Options Preferences. In the Menu bar at the top of the screen, click Firefox and select Preferences. You can set Firefox to automatically clear the cache when Firefox closes: Next to Time range to clear, choose Everything from the drop-down menu, select Cache in the items list, make sure other items you want to keep are not selected and then click the OK button.Click History and select Clear Recent History….(If you don't see it, click the menu button, then click Library click the menu button.) Click on the menu button to open the menu panel.Ĭlick the Library button on your toolbar.Tip: Here's another way to clear the Firefox cache: