Definition
A simple one-way stream where the server pushes events to the browser over a long-lived HTTP connection.
How it works
Plain HTTP, auto-reconnect built into the browser's EventSource, and easy to proxy/cache — perfect for feeds, notifications and progress updates that only flow server→client. If you also need client→server pushes, use WebSockets instead.
Common questions
What is Server-Sent Events?
A simple one-way stream where the server pushes events to the browser over a long-lived HTTP connection.
How does Server-Sent Events work?
Plain HTTP, auto-reconnect built into the browser's EventSource, and easy to proxy/cache — perfect for feeds, notifications and progress updates that only flow server→client. If you also need client→server pushes, use WebSockets instead.
What is Server-Sent Events used for in system design?
Plain HTTP, auto-reconnect built into the browser's EventSource, and easy to proxy/cache — perfect for feeds, notifications and progress updates that only flow server→client. If you also need client→server pushes, use WebSockets instead.