8 min readUpdated 2026-10-04
REST vs. SSE vs. WebSockets vs. Webhooks
Choosing between synchronous polling, Server-Sent Events, persistent WebSockets, and asynchronous Webhooks for real-time applications.
⚡ Architectural Verdict
Use SSE for AI token streaming. Use WebSockets for multiplayer bidirectional interaction. Use Webhooks for system event notifications.
Real-Time Architecture Decision Guide
Synchronous request-response is not always ideal for live, dynamic applications. Here is how modern real-time protocols compare:
1. Server-Sent Events (SSE)
- What it is: A persistent HTTP connection where the server pushes events to the client over
text/event-stream. - Direction: Unidirectional (Server ➔ Client only).
- Protocol: Standard HTTP/1.1 or HTTP/2.
- Why it’s winning in 2026: It is the standard protocol for AI chat and token streaming (used by OpenAI, Anthropic, and Gemini). It bypasses firewall issues, uses standard HTTP authentication headers, and has native automatic browser reconnection (
EventSource).
2. WebSockets
- What it is: A full-duplex TCP socket upgraded from HTTP (
ws://,wss://). - Direction: Bidirectional (Server ⇄ Client).
- When to use: When the client must stream continuous real-time data to the server (e.g. multiplayer games, collaborative canvas tools like Figma, financial order book trading).
3. Webhooks
- What it is: Reverse HTTP calls: When an event occurs on Server A, it sends an HTTP POST request to a pre-configured URL on Server B.
- Direction: Asynchronous server-to-server.
- When to use: Payment confirmations (Stripe), code pushes (GitHub), SMS delivery receipts (Twilio).