WebSocket与SSE：实时通信方案选型指南
WebSocket vs SSE: Real-Time Communication Selection Guide
| iDev Tech | 2026-07-05T10:00:00
对比WebSocket和Server-Sent Events两种实时通信技术的原理、优劣和适用场景。
Comparing WebSocket and Server-Sent Events: principles, tradeoffs, and use case selection for real-time communication.
WebSocketWebSocket提供全双工通信通道，客户端和服务端可以随时互相发送消息。基于TCP长连接，初始通过HTTP Upgrade握手建立。优势：双向实时通信、低延迟、二进制数据支持。劣势：需要专门的服务器支持、负载均衡配置复杂、连接状态管理开销大。适合：聊天应用、在线游戏、协作编辑。Server-Sent EventsSSE是基于HTTP的单向推送技术（服务端→客户端）。使用标准HTTP连接，天然支持断线重连和事件ID。优势：实现简单、HTTP兼容（穿透代理和防火墙）、自动重连。劣势：单向通信、仅支持文本数据、并发连接数受浏览器限制（每域名6个）。适合：实时通知、数据流展示、AI流式响应。选型决策树需要双向通信？→ WebSocket。只需服务端推送？→ SSE。需要二进制数据？→ WebSocket。需要穿透企业防火墙？→ SSE。AI聊天流式输出？→ SSE（大多数LLM API都使用SSE）。
WebSocketWebSocket provides full-duplex communication, allowing both client and server to send messages at any time. Built on TCP long connections with initial HTTP Upgrade handshake. Strengths: bidirectional real-time communication, low latency, binary data support. Weaknesses: requires specialized server support, complex load balancer configuration, connection state management overhead. Best for: chat apps, online games, collaborative editing.Server-Sent EventsSSE is an HTTP-based unidirectional push technology (server → client). Uses standard HTTP connections with native reconnection and event ID support. Strengths: simple implementation, HTTP compatible (traverses proxies and firewalls), automatic reconnection. Weaknesses: unidirectional only, text data only, browser connection limits (6 per domain). Best for: real-time notifications, data stream display, AI streaming responses.Decision TreeNeed bidirectional communication? → WebSocket. Server push only? → SSE. Need binary data? → WebSocket. Need to traverse enterprise firewalls? → SSE. AI chat streaming output? → SSE (most LLM APIs use SSE).