| Application Load Balancer (ALB) | Network Load Balancer (NLB) |
|---|
| ALB works at layer 7 | NLB works at layer 4 |
| Instance Id, IP address, and lambda function are types of resources specified as ALB targets | Instance Id and IP address are types of resources specified as NLB targets |
| HTTP and HTTPS protocols are supported by ALB | TCP and UDP protocols are supported by NLB |
| PrivateLink support is not supported by ALB | PrivateLink support is supported by NLB |
| Static IP is not supported by ALB | Static IP is supported by NLB |
| HTTP header-based routing is supported by ALB | HTTP header-based routing is not supported by NLB |
| The option for source IP address preservation is enabled by default for the Application Load Balancer. The X-Forwarded-For request header is automatically added and helps you with source IP preservation | Network Load Balancers can preserve the source IP address of clients when routing requests to backend targets |