Server-sent events

Traditionally, a web page has to send a request to the server to receive new data; that is, the page requests data from the server. With server-sent events, it's possible for a server to send new data to a web page at any time, by pushing messages to the web page. These incoming messages can be treated as Events + data inside the web page.

Concepts and usage

To learn how to use server-sent events, see our article Using server-sent events.


Defines all the features that handle connecting to a server, receiving events/data, errors, closing a connection, etc.



Specification Status Comment
HTML Living Standard
The definition of 'Server-sent events' in that specification.
Living Standard

See also


Other resources