Note that when you follow these steps, your history and saved passwords will be preserved.
It is critical that after clearing the data, you quit Safari. On a Mac that means to press Cmd+Q or click on Safari in the menu bar and click Quit Safari.
Click on Safari in the menu bar then select Settings...
Select Privacy then click on 'Manage Website Data...'
Click 'Remove All'
Click 'Remove Now'
Click 'Done'
Next, select 'Advanced' then check 'Show features for web developers'
Click on Develop in the menu bar and then select 'Empty Caches'
Click on Safari in the menu bar and select 'Quit Safari' or you can click Cmd+Q
