Browsers don't time out ongoing requests once it's receiving the body (not sure if there's a maximum time for receiving all the headers). ISPs may drop idle con

Browsers don't time out ongoing requests once it's receiving the body (not sure if there's a maximum time for receiving all the headers). ISPs may drop idle connections after periods of inactivity, especially if they use CGNAT. Since my app runs on LAN, there's no such problem, I don't do any heartbeat and I often pick up right where I left off the previous day. Heartbeats are easy too if necessary: just send <!----> periodically.