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Deep Patel
10/08/2025
7 min read

Understanding API Gateway: REST API vs HTTP API vs WebSocket

A simple and beginner-friendly guide to choosing between REST API, HTTP API, and WebSocket API in Amazon API Gateway.

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Understanding API Gateway: REST API vs HTTP API vs WebSocket

Amazon API Gateway is a popular AWS service that helps you create and manage APIs for web, mobile, and serverless applications.

But choosing between REST API, HTTP API, and WebSocket API can be confusing.

Let’s break it down 👇

What is Amazon API Gateway?

Amazon API Gateway acts as a front door for your backend services such as:

  • AWS Lambda
  • EC2
  • ECS
  • Any HTTP endpoint

    • It handles routing, security, scaling, and monitoring so you can focus on building features.

    REST API

    Best for: Complex & enterprise-grade APIs

    REST API is the most feature-rich option in API Gateway.

    Key points

  • Full REST support (resources & methods)
  • API keys and usage plans
  • Request/response transformation
  • Advanced authorization (IAM, Cognito, Lambda Authorizer)
  • Caching support

    • When to use

  • You need advanced API management features
  • You want fine-grained control over requests and responses
  • You’re building large or legacy REST APIs

    • ⚠️ Slightly higher cost and latency compared to HTTP API

    HTTP API

    Best for: Modern serverless APIs

    HTTP API is a lightweight, faster, and cheaper alternative to REST API.

    Key points

  • Lower latency and cost
  • Simple routing
  • Native Lambda integration
  • JWT authentication (Cognito / OAuth 2.0)
  • Built-in CORS support

    • When to use

  • You’re building serverless or microservices-based APIs
  • You don’t need advanced REST features
  • Cost and performance matter

    • 🚀 Recommended choice for most modern applications.

    WebSocket API

    Best for: Real-time communication

    WebSocket API enables persistent, bidirectional communication between clients and servers.

    Key points

  • Real-time data exchange
  • Persistent connections
  • Event-based routes: '$connect', '$disconnect', '$default'
  • Works well with Lambda and DynamoDB

    • When to use

  • Chat applications
  • Live notifications
  • Online games
  • Real-time dashboards

    • Quick Comparison

    FeatureREST APIHTTP APIWebSocket API
    ProtocolHTTPHTTPWebSocket
    Cost💰 High💵 Low💰 Medium
    Latency⚡ Medium⚡ Low⚡ Very Low
    Real-time support❌ No❌ No✅ Yes
    API Keys & Usage Plans✅ Yes❌ No❌ No
    Request/Response Transformation✅ Yes⚠️ Limited⚠️ Limited
    Best Use CaseComplex enterprise APIsServerless & microservicesLive apps, chat, real-time dashboards

    Which One Should You Choose?

  • Choose REST API for advanced control and enterprise needs
  • Choose HTTP API for fast, low-cost serverless APIs
  • Choose WebSocket API for real-time applications

    • Many production systems use a mix of these, depending on the use case.

    Final Thoughts

    Choosing the right API Gateway type impacts cost, performance, and scalability.

    For most modern AWS projects, HTTP API is the best starting point, while WebSocket API is ideal for real-time use cases.

    Happy building 🚀

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