I have lik 100+ tabs opened for a long time (1year+) and thought I would delete the cookies to give my Safari a fresh air. If I got to: Safari->Preferences->Privacy->Manage Website Data and choose "Remove All" what going to happen? Will I lose any setup, tabs, bookmarks? I once did a "Clear History and Website Data" on iOS thinking it will delete the cookies and lost all my opened tabs in Safari, I do not wish to face similar fate here. EDIT: I did it and nothing happened to my open tabs neither the history or bookmarks. I also cleared the history. Bad news is that there is no noticeable performance gains.