In Firefox:

In the 'History' tab, select 'Clear Recent History':

Make sure that 'Cookies', 'Cache', 'Active Logins', and 'Offline Website Data' are selected:

Then in the Firefox main menu, select 'Preferences':

Under 'Advanced', go to the 'Network' tab and clear the 'Cached Web Content' and the 'Offline Web Content and User Data':

For Chrome:

In the Chrome main menu, select ' Clear Browsing Data'. Make sure that 'Cached Images and Files', 'Cookies and Other Site Data', and 'Autofill Form Data' are selected:

You can also get there by going in the Chrome main menu, and by selecting 'Preferences':

Select 'Advanced' to drop-down the below menu. Select 'Privacy and Security':

Select 'Clear Browsing Data':

***Don't forget to restart your browser after you clear your cache!***