The US viewers can watch the UFC 252 event through the usual channels including Fox Sports and ESPN. But these only open access to the preliminary fights. Purchasing the PPV package is a crucial thing to do to enjoy the main event. The matchups of the UFC 252 will be part of the Fight Pass library in roughly a month after the actual event. So, if you have the Fight Pass credentials, you will be able to watch all the replays in one month later. UFC Fight Pass also provide the preliminary fights for free. If you are the subscriber, you are in luck. You can also view some of the preliminary fights via FOX Sports GO digital streaming service. Keep in mind that the PPV is the only official way to watch UFC 252 Main event live.