In addition to revealing the PS5 specs, Sony Interactive Entertainment has confirmed that while the PlayStation 5 will be backwards compatible with the PS4, the backwards compatibility won't be 100%, at least not at launch. That said, Sony does note that most of the top 100 games on PS4 -- measured by play time -- will be playable on PS5 when the console launches later this year. Beyond this, games will need to be handled on a game-by-game basis. In other words, there won't be universal backwards compatibility with the PS4, and according to Sony, this is at least partially because the PS5 is actually too fast for certain titles.
For the sake of comparison, the Xbox Series X will be fully backwards compatible with the Xbox One, and will offer a similar game-by-game basis for Xbox 360 and original Xbox games. In other words, in this department, it appears the Xbox Series X has bested the PS5.
As for whether the console will support any type of backwards compatibility with the PS3, PS2, or PS1, Sony doesn't say. That said, while there are rumors suggesting the console will have some level of backwards compatibility with these legacy consoles, many have suggested these rumors are asinine, including the developers Kotaku's Jason Schreier has spoken with.
I’ve asked a few folks in the know about the PS1-PS3 rumors and while nobody could guarantee they weren’t true (most people aren’t briefed on every single detail of the console), they did all laugh at the idea. Seems like nonsense to me— Jason Schreier (@jasonschreier) March 18, 2020
Of course, given the fact that Sony has talked about PS5 backwards compatibility on multiple occasions already, without mentioning the PS3, PS2 or PS1, suggests there's nothing to say on this front. However, it's also possible these details are still being worked out or being saved for a bigger splash later down the road.
The PlayStation 5 is set to release sometime this holiday season, and is reportedly still on track to release during this window, despite the coronavirus pandemic.
For more news, media, rumors, and leaks on the PS5, be sure to take a second and peruse all of our past and recent coverage of the console by clicking right here. Meanwhile, here's a list of every PS5 game confirmed so far.