API Gateway WebSocket API versus AppSync

05 Nov 2025

Learn how API Gateway WebSocket API differs from AppSync.

	API Gateway WebSocket API	AppSync
Type	Websocket	GraphQL
HTTPS/TLS	✅	✅
Backends	✅ Lambda ✅ Public endpoint ✅ Private endpoint ✅ AWS Service APIs	✅ Lambda ✅ Public endpoint ❌ Private endpoint ✅ AWS Service APIs
Costs	💰	💰💰💰
Maturity	⭐️⭐️⭐️⭐️	⭐️⭐️⭐️⭐️
Authentication	✅ IAM ❌ API Key ❌ OpenID Connect ❌ SAML ❌ Social ✅ Custom	✅ IAM ✅ API Key ✅ OpenID Connect ✅ SAML ✅ Social ✅ Custom
Tenant-based Throttling	❌	❌
Request Validation	✅	✅
Req./Res. Transformation	✅	✅
Endpoints	✅ Public ❌ Private	✅ Public ❌ Private
WAF	❌	✅

Further reading