WebSocket vs Server-Sent Events: Choosing the Right Real-Time Pattern for Your App

There's a moment in every web developer's career when a client says, "Can we make this update in real time?" — and you realize polling every five seconds isn't going to cut it anymore. That moment is when you need to make a clear-headed decision: WebSocket or Server-Sent Events (SSE)? Both solve real-time communication, but they do it differently, and picking the wrong one creates architectural headaches down the road. This article breaks down both technologies with practical code examples, real trade-offs, and clear guidance on when to use each. What Problem Are We Actually Solving? Traditional HTTP is a request-response protocol. The browser asks, the server answers, the connection closes. For live dashboards, notifications, collaborative tools, or live feeds, this model falls apart. You need the server to push data to the client without waiting for a request. Two mature solutions exist for this: WebSocket — a full-duplex, persistent TCP connection Server-Sent Events (SSE) — a unidir