How to clear cache in Firefox

• Click on the 3 line menu button and choose Preferences.
  
• Click on Options
  
• Select the Privacy & Security panel.
  In the Cached Web Content section, click Clear Now.
  Close the page. Any changes you've made will automatically be saved.
  

You can set Firefox to automatically clear the cache when Firefox closes:

• Click the Menu button and choose Preferences.
  
• Click on Options
  
• Select the Privacy & Security panel.
  
• In the History section, set Firefox will to Use custom settings for history.
  

• For more information on the other preferences, see Delete browsing, search and download history on Firefox.

Tip: There are several add-ons available that will allow you to clear the cache using an icon on your toolbar. Go to the Mozilla Add-ons Web Page to do a search.