You’re right. Hotwire (specifically Turbo Streams) does use WebSockets under the hood when available. And yes, Rails has background jobs, ActiveJob, and other robust primitives that Phoenix was inspired by.

That said, the key difference is not whether both use WebSockets, but how deeply integrated and unified the real-time model is in Phoenix. LiveView is not a separate layer bolted onto traditional Rails views. It is part of the core rendering lifecycle. Every UI update, state diff, and event is handled natively within the same process, leveraging the BEAM’s concurrency and fault-tolerance.

In Rails, Hotwire sits on top of the request–response model, giving you partial reactivity without rearchitecting how views work. It is elegant, but still a composition of multiple layers (Turbo, Stimulus, ActionCable).

Phoenix LiveView, on the other hand, was designed from the ground up around real-time stateful components, which leads to fewer moving parts, no client-side JS framework to maintain, and native process isolation per connected user.

So while they share concepts, the philosophy and architecture diverge. LiveView feels closer to a full reactive runtime, not just HTML over the wire.

P.S: I do love rails