Firefox: How do I clear cache on a Mac?

Step 1: Click Firefox at the top of the page and select Preferences.

Step 2: Select the Privacy tab, and then select clear all current history. 
From here, you can choose a setting to manage your browsing history.

Step 3: Select the time range to clear and then click the Clear Now button.

Step 4: From the Privacy tab, click Remove individual cookies and then:

Select Remove All Cookies; or

Select Remove Cookie to remove individual cookies.

Step 5: Close all pop-up windows. For best results, restart your browser.