We answer the question and discuss all the reasons behind GTA Online's lack of crossplay.
Are you a fan of GTA Online, eagerly waiting to play with your friends across different gaming platforms? You're not alone. Many players have been wondering if GTA Online, the multiplayer component of GTA 5, supports crossplay functionality.
Does GTA Online have crossplay?

GTA 5 and GTA Online do not have crossplay functionality as of yet.
Whether this is a good or bad thing is debatable. In certain directions, so to speak, crossplay is impossible. Feature parity between the Enhanced Edition (i.e. PS4, Xbox One and PC versions) and the launch version (on PS3 and Xbox 360) never existed, and for many years now the current-generation consoles and PC have received updates not released on PS3 and Xbox 360.
Therefore it would be functionally impossible for PS3 and PS4 players, or Xbox 360 and Xbox One players to play together.
Crossplay between current systems is possible, however many players argue that crossplay involving PC would cause more issues than benefits. The PS4 and Xbox One versions of GTA Online barely see any hacks or cheating, due to it being infinitely harder to pull off on the newer consoles. On PC though, despite Rockstar's best efforts and recent successes in quelling cheating, there are still a lot of hackers around.
Enabling crossplay would simply expose PS4 and Xbox One players to PC hackers as well, making these platforms less safe.
As for crossplay between PS4 and Xbox One players, there aren't any obstacles, but so far Rockstar hasn't decided that developing the feature is worth the trouble. On a programming level, implementing crossplay isn't a simple task, especially after the fact. When you are developing a game from the ground up, it's simpler — but still not easy — to bake crossplay into the code from the get-go.
And it's not like the game suffers from a shortage of players on any platform, such that a boost from other platforms is required. GTA Online is more popular than ever, and only growing. You won't have trouble finding other players on either Xbox One or PS4.