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
For example I have a small side project using LiveView where users would typically pull their phone out, quickly record data, then put it away again. But due LiveView only working with a connected websocket they often have to wait ~1s for the socket to reconnect, and get an annoying error message while it does.
I'm sure there's more I could do to configure this but the default at least is terrible. I believe with Hotwire I wouldn't have this problem, my view would just work and then restore the websocket when it can.
I use Phoenix and LiveView for a lot but I wish we could get more of these rough edges polished up.
You might find Hologram interesting for this use case - it transpiles Elixir to JavaScript so your UI runs client-side. No persistent connection needed, so no reconnection delays or error messages. Still write in Elixir, still communicate with the server when needed.
It's early stage with some rough edges, but there are already Hologram apps in production: https://hologram.page
This particular bit does seem interesting and would make sense to take advantage of the BEAM's cheap green threads. Couldn't find any info on LiveView's GitHub landing page nor the Phoenix website (haven't dug too much), do you happen to have a link?
In short it means you don't have to do any manual diffing, just let the compression do it for you, and have something on the client like morph to merge it in to the dom. It's way more bandwidth efficient as compression is at the byte/char level not at the semantic html level (and not per message but over the whole stream).
Where's the facepalm emoji?
Rails Hotwire uses websockets... The research done here seems to be so basic it literally missed something written on hotwired.dev's landing page, albeit it's mentioned far down enough you have to scroll a teeny tiny bit (half a page on my screen)...
Rails also has background jobs and all the other things considering Phoenix is modeled after Rails.