There are some situations where a poor network connection could cause clients to have issues maintaining a stable connection. That said it's very likely that if the client has a stable websocket connection, their messages will be received and in the order we received them, however, we don't provide any guarantees about this.

We consider our platform to be extremely reliable, and many businesses such as GoGurdian, Draftkings, and Invision depend on our infrastructure for their services. But due to a large number of factors outside of our control, we can't make any kind of guarantees around individual message delivery.

However, the Pusher platform is extremely flexible. If delivery is vital, there's nothing preventing you from implementing some safeguards yourself. You could, for example, implement client-side acknowledgments to let the server know when messages are received, and retry in the event of a failure.