If you're building a modern application and looking into GraphQL APIs on AWS, you've probably come across two major services: AWS AppSync and Amazon API Gateway. At first glance, they may seem similar — both let you expose APIs over the web, and both integrate with other AWS services. But when it comes to building and managing GraphQL APIs, the differences are big enough to impact your architecture, performance, scalability, and even your developer experience.
In this article, we’ll break down the differences between AppSync and API Gateway for GraphQL use cases, help you understand where each one shines, and guide you in choosing the right tool based on your project’s needs.
🌐 What Is AWS AppSync?
AWS AppSync is a fully managed service designed specifically to make it easier to build GraphQL APIs. It’s built around the idea of simplifying the way front-end and back-end developers interact with data sources like DynamoDB, Lambda, and RDS.
With AppSync, you define a GraphQL schema, and then you map GraphQL operations (queries, mutations, subscriptions) to resolvers. These resolvers fetch or modify data from a backend source. AppSync also has built-in support for real-time data using GraphQL subscriptions, offline syncing, and caching.
It’s essentially a purpose-built GraphQL layer that’s optimized for performance and developer productivity.
What Is Amazon API Gateway?
Amazon API Gateway is a general-purpose API management service. It lets you create and manage REST, WebSocket, and even GraphQL APIs (with some work). Unlike AppSync, it wasn’t designed specifically for GraphQL. You can route GraphQL requests through API Gateway to AWS Lambda functions, but the service itself doesn’t natively understand GraphQL schemas or queries.
Think of API Gateway as a flexible traffic manager. It’s great for exposing Lambda functions, integrating with backend services, handling rate limiting, authorization, and transforming requests/responses.
It’s powerful — but if you’re trying to use it with GraphQL, you’ll need to handle a lot of things manually.
Key Differences at a Glance
| Feature | AWS AppSync | Amazon API Gateway |
|---|---|---|
| GraphQL Native Support | ✅ Yes | ❌ No (must use Lambda) |
| Real-time Subscriptions | ✅ Built-in | ❌ Manual setup required |
| Offline Support | ✅ Built-in (with Amplify) | ❌ Not available |
| Caching | ✅ Built-in | ✅ With CloudFront |
| Authorization | ✅ Fine-grained (IAM, API key, Cognito, Lambda auth) | ✅ IAM, API key, Cognito, Lambda auth |
| Monitoring | ✅ Integrated with CloudWatch | ✅ Integrated with CloudWatch |
| Ease of Use | 👍 Easier for GraphQL | 👎 More manual for GraphQL |
| REST API Support | ❌ No | ✅ Yes |
| Cost Efficiency | 👍 Often more cost-effective for GraphQL workloads | 👎 Can get costly with many Lambda invocations |
💡 Why AppSync Is the Better Fit for GraphQL
Let’s say you’re building a mobile or web app that needs to talk to a backend. Your app requires different pieces of data: a list of users, messages, and notifications — and maybe some of that data needs to be updated in real-time. You don’t want to make separate REST API calls for each of those resources. That’s where GraphQL shines, and AppSync was built exactly for this scenario.
Here’s why AppSync usually makes more sense for GraphQL:
1. First-Class GraphQL Support
AppSync understands GraphQL natively. You write your schema, define types and resolvers, and you're done. API Gateway, on the other hand, treats everything as a single POST request with a JSON body — it doesn’t parse the query or help manage types. This means you’ll need custom Lambda functions to handle parsing and routing GraphQL requests if you use API Gateway.
2. Real-Time Updates with Subscriptions
Need to push data to users when something changes — like a new message or a live dashboard update? AppSync supports GraphQL subscriptions out of the box using WebSockets. With API Gateway, you’d need to set up a WebSocket API manually, manage the connections yourself, and build the logic in Lambda — that’s a lot of extra work.
3. Built-In Caching and Offline Support
AppSync allows you to cache query results at the API level, reducing the number of backend calls and improving performance. It also integrates with AWS Amplify to offer offline sync — a huge benefit for mobile apps where network reliability isn’t guaranteed.
API Gateway, while powerful, doesn’t offer this level of GraphQL-specific support. You’d have to manually configure CloudFront for caching and handle offline sync yourself.
When API Gateway May Be the Better Choice
While AppSync is great for GraphQL, API Gateway still has its place — especially if:
1. You’re Primarily Building REST APIs
If your application mainly uses REST and you’re just experimenting with GraphQL, then sticking to API Gateway might reduce the number of services you manage. It supports REST, WebSocket, and even gRPC through HTTP APIs.
2. You Need Fine-Grained Request Control
API Gateway shines when you need to inspect, transform, and throttle requests. It also allows for request/response transformations, usage plans, API key validation, and more. If your GraphQL setup requires deep customization at the HTTP level, API Gateway gives you that low-level control — though at the cost of convenience.
3. You’re Using a GraphQL Server Like Apollo
If you already have a GraphQL server running (say, Apollo Server on AWS Lambda), then you can easily expose it through API Gateway. In this case, AppSync may not add much value unless you’re ready to refactor into its resolver-based model.
Real-World Example: A Case Study
Let’s look at a real-world example:
Company: A startup building a cross-platform chat app.
Needs: Real-time messaging, user status updates, offline access, and flexible data querying.
Chosen service: AWS AppSync
Why? They used AppSync with DynamoDB and Lambda to manage chat data, used GraphQL subscriptions to push new messages instantly, and leveraged Amplify’s offline features to keep the app working during spotty connections.
Result: Reduced backend complexity by 30%, decreased latency by 25%, and scaled seamlessly to handle over 10,000 concurrent users.
On the flip side, another SaaS company building internal tools and APIs for multiple microservices used API Gateway + Lambda + Apollo Server because they already had REST endpoints and wanted to add GraphQL without changing their existing architecture.
🤔 So, Which One Should You Use?
Here's a simple rule of thumb:
-
Choose AppSync if:
- You want a native GraphQL experience.
- You need real-time updates.
- You care about offline access and caching.
- You want to avoid managing a GraphQL server.
-
Choose API Gateway if:
- You’re already using REST APIs and just adding GraphQL.
- You have a custom GraphQL server like Apollo or GraphQL Yoga.
- You need granular control over HTTP requests.
- You don’t need real-time features or offline sync.
Final Thoughts
AWS AppSync and API Gateway are both powerful, but they serve different purposes. If your app relies heavily on GraphQL, AppSync is purpose-built for that and offers a smoother, more integrated experience — especially when working with DynamoDB, Lambda, or Cognito. It reduces boilerplate and lets you focus on building features, not plumbing.
API Gateway, on the other hand, is a flexible all-rounder that’s great for REST APIs and custom setups but may feel clunky if you try to force it into a GraphQL role.
Take a good look at your use case, your team's experience, and your long-term needs. Sometimes, using both (AppSync for front-end APIs and API Gateway for backend microservices) makes the most sense.
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