Keep-Alive

ELI5 — The Vibe Check

Keep-Alive tells the server 'don't hang up after this request — I've got more coming.' Instead of opening a new TCP connection for every request (expensive!), you reuse the same one. It's like keeping the phone line open instead of hanging up and redialing for every sentence.

Real Talk

HTTP Keep-Alive (persistent connections) reuses TCP connections for multiple HTTP requests/responses, avoiding the overhead of TCP handshakes and TLS negotiations for each request. Default in HTTP/1.1, configurable via Connection and Keep-Alive headers. Superseded by HTTP/2's single multiplexed connection.

When You'll Hear This

"Keep-Alive reduced our API latency by eliminating repeated TCP handshakes." / "In HTTP/2 you get one connection period — Keep-Alive is a solved problem."