API Gateway HTTP API versus ALB WebSocket

29 Oct 2025

Learn how API Gateway HTTP API differs from ALB WebSocket.

	API Gateway HTTP API	ALB WebSocket
Type	REST API	Websocket
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