# SSE vs webSocket vs Long Polling

I was learning SSE today, and kinda confused about the SSE with other server-client communication methods, so here is short summary of the learning outcome.

This post is a **shallow comparison** between the normal **http requests**, **short polling**, **long polling**, **webSocket**, and **SSE.**

* **Communication Method**
    
    * **HTTP Requests:** One-way request/response.
        
    * **Short Polling:** One-way request/response.
        
    * **Long Polling:** One-way request/response.
        
    * **WebSocket:** Full-duplex, bidirectional communication.
        
    * **SSE:** One-way communication (server to client).
        
* **Connection Persistence**
    
    * **HTTP Requests:** A new connection is established for every request.
        
    * **Short Polling:** Each request closes after completion.
        
    * **Long Polling:** Each request closes after completion.
        
    * **WebSocket:** Persistent connection until explicitly closed.
        
    * **SSE:** Persistent connection until explicitly closed.
        
* **Real-Time Capability**
    
    * **HTTP Requests:** Low (requires new requests after each response).
        
    * **Short Polling:** Medium (depends on polling frequency).
        
    * **Long Polling:** Medium-High (server can push data proactively).
        
    * **WebSocket:** Very high (minimal latency).
        
    * **SSE:** Medium-High (server can push data proactively).
        
* **Performance**
    
    * **HTTP Requests:** High overhead (frequent connection setup).
        
    * **Short Polling:** Medium (frequent requests).
        
    * **Long Polling:** Lower (reduces unnecessary requests).
        
    * **WebSocket:** Optimal (single connection, low overhead).
        
    * **SSE:** Efficient (single connection, low overhead).
        
* **Use Cases**
    
    * **HTTP Requests:** Static data fetching or short-lived interactions.
        
    * **Short Polling:** Scenarios with infrequent data updates (e.g., weather updates).
        
    * **Long Polling:** Applications needing real-time updates (e.g., chat systems).
        
    * **WebSocket:** High-frequency, real-time bidirectional data exchange.
        
    * **SSE:** One-way real-time data streams (e.g., notifications, live feeds).