
Any changes you've made will automatically be saved.
Click OK to close the Settings for Clearing History window. For more information about other settings, see Delete browsing, search and download history on Firefox. Put a check mark next to Cache and make sure other items you want to keep are not selected. The Settings for Clearing History window will open. Select the check box for Clear history when Firefox closes. 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. You will see an Apple logo and a progress bar on your screen. Next, press the key combination CMD + Option + P + R. Next, turn the Mac on by pressing the Power button.
Click the menu button and select Settings. In order to do this, you have to go to the Apple menu and click Shut Down.
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….Click the menu button to open the menu panel.Tip: Here's another way to clear the Firefox cache: