Must websockets have heartbeats? : <p>When I read about websockets, heartbeats are usually mentioned as a must have. MDN even writes about a <a href="https://developer.mozilla.org/en-US/docs/Web/API/WebSockets_API/Writing_WebSocket_servers#Pings_and_Pongs_The_Heartbeat_of_WebSockets" rel="noreferrer">special opcode for heartbeats</a>.</p>

<p>But are heartbeats a mandatory part of websockets? Do I <em>have to</em> implement it or else my websockets will be terminated by the browsers or some other standards?</p>
