https://www.polygon.com/fortnite/2018/9/26/17905150/sony-fortnite-ps4-cross-platform-play-open-beta

Sony has finally stopped fighting the future: A beta for cross-platform play, including support for Fortnite, launches today.

“The first step will be an open beta beginning today for Fortnite that will allow for cross platform gameplay, progression and commerce across PlayStation 4, Android, iOS, Nintendo Switch, Xbox One, Microsoft Windows, and Mac operating systems,” PlayStation president and global CEO John Kodera wrote on the PlayStation Blog. “We see the beta as an opportunity to conduct thorough testing that ensures cross-platform play is best on PlayStation, while being mindful about the user experience from both a technical and social perspective.”