How to Clear Your Browser Cache - Mozilla Firefox
At the top-right corner of your browser window, there will be an icon made up of three horizontal lines. Click the icon and a drop-down menu should appear. Find the History option in the middle of the drop-down menu and select it. See below image.
Another menu should appear. Choose the second option labeled Clear Browsing History
A last window will pop up prompting you to choose Time range to clear. in this instance, you would choose Everything. See below.
Make sure Browsing & Download History, Cookies, and Cache are all checked. You may choose more if you want, but these are the minimum we recommend.
Then hit Clear Now.
Finally, refresh the window you were working on and you should see any updates that you did not see before.