When you’re building APIs on AWS, Amazon API Gateway gives you two main options: HTTP API and REST API.
At first glance, they sound interchangeable. In reality, they’re built with very different priorities. Choosing the right one early can save you cost, reduce latency, and simplify your architecture. Choosing the wrong one can do the opposite.
This post breaks down the real differences, the trade-offs, and how to decide which one actually fits your use case.
Understanding the intent behind both APIs
AWS didn’t create HTTP API to replace REST API. They created it to solve a different problem.
- REST API came first. It was designed for full API management with fine-grained control.
- HTTP API came later, optimized for modern, serverless, high-performance APIs where simplicity matters more than exhaustive features.
Think of it like this:
REST API is a Swiss Army knife. HTTP API is a sharp, well-balanced chef’s knife.
What is an HTTP API?
HTTP API is a lightweight version of API Gateway focused on speed, simplicity, and cost efficiency.
It removes many advanced features and focuses on what most applications actually use today.
Key characteristics
- Lower latency
- Significantly cheaper pricing
- Simple routing model
- Native support for JWT authorization
- Seamless Lambda and HTTP integrations
Typical use cases
- Backend-for-frontend APIs
- Serverless microservices
- Mobile and web application backends
- Internal APIs between services
If your API mostly does:
- Request → Lambda → Response then HTTP API is usually the best choice.
What is a REST API?
REST API is the original and most feature-rich offering in API Gateway.
It gives you deep control over how requests are processed, secured, transformed, cached, and throttled.
Key characteristics
- Advanced request/response mapping
- API keys and usage plans
- Built-in caching
- Fine-grained throttling
- Integration with AWS WAF
- Support for complex authorization flows
Typical use cases
- Public APIs exposed to external customers
- SaaS platforms with per-customer rate limits
- APIs that require transformations before reaching backend services
- Compliance-heavy or enterprise systems
REST API shines when governance and control matter more than raw performance.
Feature-by-feature comparison
Cost
- HTTP API is significantly cheaper, especially at scale.
- REST API costs more due to additional processing layers.
If you expect high traffic, cost difference becomes very noticeable.
Performance & latency
- HTTP API has lower latency due to a simpler internal pipeline.
- REST API introduces additional overhead for features like mapping and caching.
For frontend-heavy apps, HTTP API usually feels snappier.
Authorization
-
HTTP API
- JWT authorizers
- IAM
- Lambda authorizers
-
REST API
- IAM
- Cognito
- Lambda authorizers
- API keys
If you rely on JWT-based auth (common in modern apps), HTTP API works very well.
Request & response transformation
- HTTP API: minimal transformation support
- REST API: powerful Velocity Template Language (VTL) mappings
If you need to reshape payloads heavily before or after Lambda execution, REST API is the better choice.
Caching and throttling
- HTTP API: no built-in caching, basic throttling
- REST API: full caching and advanced throttling controls
Caching at the gateway level is one of the biggest reasons teams still choose REST API.
Choosing the right one: a practical decision framework
Choose HTTP API when:
- You’re building a modern serverless application
- You want lower cost and better performance
- Your backend is mostly Lambda or HTTP services
- You don’t need API keys or caching
- Simplicity matters
Choose REST API when:
- You’re exposing APIs to third-party customers
- You need API keys and usage plans
- You require caching at the gateway
- You need advanced request transformations
- Security and governance are critical
A real-world example
Imagine you’re building a SaaS inventory system:
- Frontend: Next.js
- Backend: Lambda + database
- Auth: JWT-based login
- APIs: Products, orders, invoices
In this case:
- HTTP API is faster
- HTTP API is cheaper
- HTTP API is simpler to maintain
Now imagine you expose a public API to partners:
- Each partner has a quota
- Requests must be throttled
- Responses must be transformed
- WAF protection is required
That’s where REST API makes sense.
Common misconception
A lot of developers think:
“REST API is more ‘RESTful’ than HTTP API.”
That’s not true.
Both can implement REST principles. The difference is capability, not architectural style.
Final thoughts
Most modern applications do not need everything REST API offers.
That’s why AWS introduced HTTP API in the first place.
My rule of thumb:
- Start with HTTP API
- Upgrade to REST API only when a specific feature forces you to
This keeps your architecture lean, fast, and cost-efficient.