WebSocket is a protocol over http. You should read: https://developer.mozilla.org/en-US/docs/Web/API/WebSockets_API for more info on WebSocket.
Krunker uses msgpack for decoding and encoding packets. Msgpack is also smaller and sometimes faster depending on the implementation you use/make.
Like I said earlier, Krunker uses msgpack for decoding and encoding packets. A ping packet would like this: ["po"] which you send when you get a ["pi"] packet, and the ping result packet you receive is ["pir", ]. For fetching a profile, you can use ["r", "profile", , null]. The result packet would be like ["0", "profile", , , , , ...etc]. For finding packets, you can download https://krunker.io/social.html using a command like cURL, formatting the file and lo