WebSocket vs REST API: Key Differences & Comparison

WebSocket vs REST API

Learn the Basics of Web Communication

How Do Apps Talk to Servers?

Before diving into the code, it's crucial to understand how modern applications exchange data. The two most common protocols are REST and WebSocket.

What is REST API?

REST: Representational State Transfer

Standard HTTP Protocol (GET, POST, PUT, DELETE)

Stateless: Note context saved between requests

Data usually formatted as JSON

The Request-Response Cycle

In REST, communication is unidirectional. The client must ask for data every single time.

What is WebSocket?

A protocol for full-duplex communication channels

Persistent Connection: Stays open after initial handshake

Real-time: Data flows instantly both ways

Ideal for scenarios requiring low latency

Continuous Connection

Once connected, the line stays open. Server pushes data without waiting for a request.

REST vs WebSocket: Key Differences

REST: Stateless (New request every time)

WS: Stateful (Remembers connection)

REST: Client initiates only

WS: Two-way (Server can push data)

REST: Higher overhead (Headers sent often)

WS: Low overhead after handshake

Protocol Efficiency Comparison

Message overhead significantly differs. REST sends heavy HTTP headers (~800 bytes) with every single request. WebSocket sends tiny frames (~2-8 bytes) after connection.

When to Use REST API

• Loading User Profiles • Submitting Web Forms • Retrieving Search Results • Caching Static Content

When to Use WebSocket

• Live Customer Support Chat • Multiplayer Online Games • Real-time Creating/Co-editing • Live Stock Price Updates

Summary

REST is simple, stateless, and good for general web requests.

WebSocket is persistent, real-time, and efficient for streaming.

Choose based on your app needs: Is it a document (REST) or a conversation (WebSocket)?