At least in a browser context, HTTP/2 doesn't address server to client unsolicitied messages. So you'd still need a polling request open from the client. HTTP/

At least in a browser context, HTTP/2 doesn't address server to client unsolicitied messages. So you'd still need a polling request open from the client. HTTP/2 does specify a server push mechanism (PUSH_PROMISE), but afaik, browsers don't accept them and even if they did, (again afaik) there's no mechanism for a page to listen for them. But if you control the client and the server, you could use it.