Clearing temporary internet files and cookies in Firefox To clear your temporary internet files and cookies in Firefox, follow these instructions: Open the Firefox browser. Click the three horizontal lines in the top right of your browser. Click 'Options' from the drop-down menu, which shows about halfway down the list. On the next page, click 'Privacy and security' from the menu on the left. Under the 'Cookies and site data' heading, click 'Clear data'. Once you've clicked 'Clear data', a box will pop up in the middle of the screen. Make sure both Cookies and site data' and 'Cached web content' are both ticked and click 'Clear'. Another box will appear. Select 'Clear now' to remove all cookies and site data stored by Firefox. Please note this may sign you out of other websites and remove offline web content. Once complete, you’ll see the 'Options' page again. At this point, close all Firefox windows and then reopen the browser. What do I do if these steps do not apply? The instructions above apply to the most recent version of Firefox. Other browsers or older versions will behave differently. If the instructions above don’t apply, you may need to update your browser. To do so, after clicking the three lines, click 'Help' and then 'About Firefox'. A pop-up displaying 'Firefox is up to date' or 'Restart to update Firefox' will then appear and you can follow the instructions to restart. If you need any further assistance, please see our contact details here. Related articles How to clear temporary internet files and cookies on an Android device Clearing temporary internet files and cookies in Safari Clearing temporary internet files and cookies in Google Chrome How do I clear my cache on the App?