Is it possible fortnite to play on the switch if the other on the ps4 fortnite is playing online?
Yes it's possible
Of course you can play on the switch while another person is playing on PS4 …
No, if I can play online with him
Then formulate your question as well. No, this is not possible
Yes, the PS4 user has to have "cross-platform groups" in the settings
Yes. Fortnite is the first game that you can play with everyone. Whether mobile phone, XBox, Playstation or Switch. All you have to do is activate in the settings "cross-platform games" or something, add your friend on Epic as a friend and shove you can gamble together!