It might still be this problem I’ve experienced. Link to my reply from 2019 Phoenix LiveView is now... live! - #30 by wanton7
For anyone trying out LiveView, WebSocket felt really slow to connect when I used localhost:4000. It seems that there is some sort of delay at least on Windows. According to this https://stackoverflow.com/questions/15135506/websocket-connection-setup-takes-a-relatively-long-time-is-this-normal it’s caused by IPv6. So if someone is experiencing this as well, use 127.0.0.1:4000 instead.
