- Click on the Tools bar (three bars in the top-right corner).
- Click History.
3. On the menu to the right, select Clear Recent History.
4. In the Clear All History menu, select the time range to Everything.
5. Select the options, Cookies, Cache, Active Logins, Site settings, and Offline website data.
6. Click OK.
7. If on a Windows computer, close and re-open Firefox to save your changes. If on an Apple computer, go to the Firefox menu on the top menu bar and select Quit for the changes to take effect.q