Server-sent events

lastmod 2024-12-30created 2019-07-159 edits

Traditionally, a web page has to send a request to the server to receive new data; that is, it requests data from the server. With Server-Sent Events, however, the server can send new data at any time without a request from the web page. Messages sent this way can be handled inside the web page as Events + data.

How it works

• Subscribing to real-time server data - Server Sent Event(SSE)

Using Server-Sent Events instead of WebSockets

• Server-Sent Events: the alternative to WebSockets you should be using (Original)

When building a real-time web application, WebSockets usually come to mind, but SSE can also be a simple alternative

• Problems with WebSockets: not based on HTTP, so they miss out on HTTP's benefits
  • No compression, poor HTTP/2 multiplexing support, not supported by proxies, hijacking possible
• Server-Sent Events(SSE)
  • Lets the server send Low-Latency push events to the client
  • An HTML standard supported by all browsers (except IE)
  • Unlike WebSockets, SSE flows in one direction, from server to client (not suitable for games that need bidirectional communication)
  • Runs over HTTP and needs no separate protocol

See also

• Server-sent events (SSE)
• Event stream format
• Push technology
• Akka:Http:SSE (how to implement SSE in akka-http)
• Mercure - an open protocol based on SSE

Favorite site

• MDN - Server-sent events - Web API
• (Web development) What is SSE ( Server-Sent Events)
• Subscribing to real-time server data - Server Sent Event(SSE)
• The underrated Server-Sent Events (SSE) technology | GeekNews