Does Call of Duty: Modern Warfare 3 have cross-platform support? Yes, Call of Duty: Modern Warfare 3 has full cross-platform support. This means that you can squad up with players on any console PlayStation, Xbox, or PC and enter the battlefield together. This is true for any online mode in the game.
This means that if you have Modern Warfare 3 on PC, you will need to purchase it on PlayStation 5 or your Xbox Series X|S if you want to play on those platforms using the same account. This is all that you need to know about Modern Warfare 3 when it comes to crossplay and cross-platform progression.