SSE

Introduction Real‑time communication is a cornerstone of modern web applications—from live dashboards and collaborative editors to multiplayer games and IoT telemetry. Over the past decade, developers have relied heavily on WebSockets for bidirectional, low‑latency messaging, while Server‑Sent Events (SSE) have emerged as a lightweight, HTTP‑based alternative for one‑way server‑to‑client streams. Both technologies have distinct strengths and weaknesses: Feature WebSockets Server‑Sent Events (SSE) Direction Full duplex (client ↔ server) Unidirectional (server → client) Transport Upgraded HTTP (WS/ WSS) Standard HTTP/HTTPS (text/event-stream) Protocol Overhead Low (binary frames) Slightly higher (text lines) Browser Support All modern browsers (including mobile) Native support in most browsers, IE 11+ Proxy/FW Friendly Can be blocked by strict proxies/firewalls Works through most proxies and CDNs Reconnection Manual handling required Built‑in automatic reconnection In practice, no single solution satisfies every scenario. Hybrid SSE architectures deliberately combine SSE with complementary transports—most commonly WebSockets or long‑polling—to achieve: ...