This page is our investigation of cross-play game Fortnite. We always verify information manually using official sources - no AI.
Fortnite didn't have cross-play support at the release, but it was added soon after approval from Sony, and covered in a PlayStation Blog article here. The article directly specifies that Fortnite received full cross-play support between PlayStation, Xbox, PC via Epic Games Store, Android, and IOS.

We can also find the cross-play information on the official Fortnite FAQ page here, which says the same things.

It is also important to mention that, per the FAQ, to play Fortnite in cross-play mode, you have to create an Epic Games account, but this is a common practice that is used by most cross-play games.