REST API vs HTTP API in AWS API Gateway: Key Differences and Usage

In AWS API Gateway, REST API supports advanced features like API keys, usage plans, and caching, while HTTP API offers a simpler, faster, and cheaper option with basic routing and JWT authorizers. Choose REST API for complex, feature-rich APIs and HTTP API for low-latency, cost-effective HTTP services.

Quick Comparison

This table summarizes the main differences between REST API and HTTP API in AWS API Gateway.

Feature	REST API	HTTP API
Protocol Support	RESTful APIs with full HTTP methods	Simplified HTTP APIs with common methods
Latency	Higher latency due to feature richness	Lower latency, optimized for speed
Cost	Higher cost per million requests	Lower cost, more budget-friendly
Authentication	Supports IAM, Lambda authorizers, Cognito, API keys	Supports JWT authorizers, Lambda authorizers, and IAM
Caching	Built-in response caching available	No built-in caching
Use Cases	Complex APIs needing fine control and features	Simple APIs needing fast, low-cost routing

Key Differences

REST API in API Gateway is designed for full-featured RESTful services. It supports advanced features like request/response transformations, API keys, usage plans, and caching. This makes it ideal when you need fine-grained control over your API behavior and security.

On the other hand, HTTP API is a newer, lightweight option focused on simplicity and performance. It supports common HTTP methods, JWT authorizers, and Lambda authorizers but lacks some advanced features like request transformations and caching. This results in lower latency and cost, making it great for simple APIs or microservices.

While REST API supports multiple authentication methods including Lambda authorizers and API keys, HTTP API currently supports JWT authorizers, Lambda authorizers, and IAM only. Also, REST API has built-in caching to improve performance, which HTTP API does not provide.

Code Comparison

Here is an example of creating a simple GET endpoint using REST API in AWS CloudFormation.

yaml

Resources:
  MyRestApi:
    Type: AWS::ApiGateway::RestApi
    Properties:
      Name: MyRestApi
  MyResource:
    Type: AWS::ApiGateway::Resource
    Properties:
      ParentId: !GetAtt MyRestApi.RootResourceId
      PathPart: hello
      RestApiId: !Ref MyRestApi
  MyMethod:
    Type: AWS::ApiGateway::Method
    Properties:
      HttpMethod: GET
      ResourceId: !Ref MyResource
      RestApiId: !Ref MyRestApi
      AuthorizationType: NONE
      Integration:
        Type: MOCK
        RequestTemplates:
          application/json: '{"statusCode": 200}'

Output

Creates a REST API with a GET /hello endpoint returning HTTP 200 OK.

HTTP API Equivalent

Here is the equivalent simple GET endpoint using HTTP API in AWS CloudFormation.

yaml

Resources:
  MyHttpApi:
    Type: AWS::ApiGatewayV2::Api
    Properties:
      Name: MyHttpApi
      ProtocolType: HTTP
  MyIntegration:
    Type: AWS::ApiGatewayV2::Integration
    Properties:
      ApiId: !Ref MyHttpApi
      IntegrationType: MOCK
      IntegrationMethod: GET
      PayloadFormatVersion: '1.0'
  MyRoute:
    Type: AWS::ApiGatewayV2::Route
    Properties:
      ApiId: !Ref MyHttpApi
      RouteKey: GET /hello
      Target: !Join ["/integrations/", [!Ref MyIntegration]]

Output

Creates an HTTP API with a GET /hello route returning a mock 200 OK response.

When to Use Which

Choose REST API when you need advanced features like API keys, usage plans, request/response transformations, or caching. It is best for complex APIs requiring fine control and multiple authentication methods.

Choose HTTP API when you want a simple, fast, and cost-effective API with basic routing and JWT, Lambda, or IAM authentication. It is ideal for microservices, low-latency applications, or when you want to minimize cost and complexity.

Key Takeaways

REST API offers rich features but with higher latency and cost.

HTTP API is simpler, faster, and cheaper but with fewer features.

Use REST API for complex, feature-rich APIs needing caching and API keys.

Use HTTP API for simple, low-latency APIs with JWT, Lambda, or IAM authentication.

Both support AWS integrations but differ in supported protocols and features.