Load balancer feature comparison

This page gives you a comparative overview of the load balancing features offered by Cloud Load Balancing. If you haven't already done so, begin by reading the following:

In the following tables, a checkmark indicates that a feature is supported. For more information about a feature, click the info link.

Type of load balancer

Feature Application Load Balancer Proxy Network Load Balancer Passthrough Network Load Balancer
Internal External Internal External Internal External
Proxy Load balancer modes:
regional
cross-region
Load balancer modes:
global
classic
regional
Load balancer modes:
regional
cross-region
Load balancer modes:
global
classic
regional
Passthrough Load balancer modes:
internal
Load balancer modes:
external

Protocols from the clients to the load balancer

This table lists the protocols supported for communication between clients and the different load balancers.

Feature Application Load Balancer Proxy Network Load Balancer Passthrough Network Load Balancer
Internal External Internal External Internal External
One of:

HTTP (HTTP/1.1)

HTTPS (HTTP/1.1)

HTTP/2 (requires TLS) including gRPC 1


No QUIC support

No QUIC support for regional mode.
HTTP/3 (based on IETF QUIC)
(Only global and classic modes)
SSL or TCP
TCP only

Regional mode: TCP only

Global and classic
mode: SSL or TCP
TCP, UDP, or L3_DEFAULT2
info

info
WebSockets

info


info

1 To support gRPC clients, create an HTTPS load balancer with HTTP/2 as the protocol from the load balancer to backends.

2 The L3_DEFAULT setting enables support for the following additional IP protocols:

  • For internal passthrough Network Load Balancers, L3_DEFAULT enables support for TCP, UDP, ICMP, ICMPv6, SCTP, ESP, AH, and GRE .
  • For external passthrough Network Load Balancers, L3_DEFAULT enables support for TCP, UDP, ESP, GRE, ICMP, and ICMPv6 .

Protocols from the load balancer to the backends

This table lists the IP protocol settings supported with backend services for different load balancers. For more reference information, see Backend services.

Feature Application Load Balancer Proxy Network Load Balancer Passthrough Network Load Balancer
Internal External Internal External Internal External
One of:

HTTP (HTTP/1.1)

HTTPS (HTTP/1.1)

HTTP/2 (requires TLS) including gRPC

One of:
SSL (TLS) or TCP
TCP, UDP, or UNSPECIFIED1
info

info
WebSockets
info

info

1 The UNSPECIFIED setting enables support for the following additional IP protocols:

  • For internal passthrough Network Load Balancers, UNSPECIFIED enables support for TCP, UDP, ICMP, ICMPv6, SCTP, ESP, AH, and GRE .
  • For external passthrough Network Load Balancers, UNSPECIFIED enables support for TCP, UDP, ESP, GRE, ICMP, and ICMPv6 .

Backends

Feature Application Load Balancer Proxy Network Load Balancer Passthrough Network Load Balancer
Internal External Internal External Internal External
Backends can be in multiple regions
(Only cross-region mode)

(Only global and
classic mode)

(Only cross-region mode)

(Only global and
classic mode)
Backends must be in one region
(Only regional mode)

(Only regional and
classic mode)

(Only regional mode)

(Only regional and classic mode)
Cloud Storage in backend buckets
(Only global and
classic mode)
External endpoints in internet NEGs
(Only regional mode)

(Global,
regional, and classic modes)

(Only regional mode)

(Only regional mode)
Multiple backend services and a URL map
Virtual machine backends on Compute Engine
Self-managed Kubernetes and GKE
Zonal NEGs
GCE_VM_IP_PORT endpoints

GCE_VM_IP_PORT endpoints

GCE_VM_IP_PORT endpoints

GCE_VM_IP_PORT endpoints

GCE_VM_IP endpoints

GCE_VM_IP endpoints
Private Service Connect NEGs
(Only global and regional mode)

(Only global and regional mode)
Private external endpoints in hybrid NEG backends
info

info

info

info
Serverless backends info
info

Health checks

For links to reference information, see Health checks.

Feature Application Load Balancer Proxy Network Load Balancer Passthrough Network Load Balancer
Internal External Internal External Internal External
gRPC health checks 2 2 2 2 2 1
HTTP health checks 3
(Only classic and regional mode)
1
HTTPS health checks 3
(Only classic and regional mode)
1
HTTP/2 health checks
(Only classic and regional mode)
1
SSL health checks 1
TCP health checks 1
Configurable health checks
Configurable request path (HTTP, HTTPS, HTTP/2)
Configurable request string or path (TCP or SSL)
Configurable expected response string 1
Distributed Envoy health checks
(Only regional mode)

(Only regional mode)

1 Backend service-based external passthrough Network Load Balancers health checks. Target pool-based load balancers only support legacy HTTP health checks.

2 Regional external Application Load Balancer does not support legacy health checks. The global external Application Load Balancer and the classic Application Load Balancer support legacy health checks only if both of the following are true:

  • The backends are instance groups.
  • The backend virtual machine (VM) instances serve traffic that uses the HTTP or HTTPS protocol.

3 Envoy-based regional load balancers (regional internal and external Application Load Balancers and regional internal and external proxy Network Load Balancers) that use hybrid NEG backends don't support gRPC health checks. For more information, see the Hybrid NEGs overview.

IP addresses

For links to reference information, see Addresses.

Feature Application Load Balancer Proxy Network Load Balancer Passthrough Network Load Balancer
Internal External Internal External Internal External
Internal IP address, accessible in your VPC network
External IP address (global anycast)
(Only global and classic1 mode)

(Only global and classic1 mode)
External IP address (regional)
(Only regional and classic2 mode)

(Only regional and classic2 mode)
External IP address from Bring your own IP (BYOIP)
(Only global and classic mode)

(Only classic mode)
Multiple forwarding rules with the same IP address, each having a unique protocol and port combination
Internet accessible3
Privately accessible
info4

info4

info4
Client source IP address preservation X‑Forwarded‑For header X‑Forwarded‑For header PROXY protocol PROXY protocol
IPv6 support
IPv6 termination
(Only global and classic1 mode)

IPv6 termination
(Only global and classic1 mode)

info

info1

1 Supported if Premium Tier is used

2 Supported if Standard Tier is used

3 Internet access is also available for clients that are in Google Cloud.

4 Private access is available in the same VPC network and from any region with global access. In cross-region mode, global access is enabled by default.

Network topologies

Feature Application Load Balancer Proxy Network Load Balancer Passthrough Network Load Balancer
Internal External Internal External Internal External
Relationships between VPC networks and load balancer backends
Backends in the same VPC network
(Only regional mode)

(Only regional mode)
Backends in multiple VPC networks1
(Only global and classic modes)

(Only global and classic modes)
Backends can use a Shared VPC network
Cross-project service referencing
info

info
(Only regional mode)
Client access to load balancers
Google Cloud or on-premises clients must access the load balancer privately2
Google Cloud client VMs require external IP addresses or a NAT solution like Cloud NAT to access the load balancer
On-premises client VMs require internet access to access the load balancer
Google Cloud client VMs can be located in any region
info

(Only global and classic3 modes)

info

info
Google Cloud client VMs can be located in any project

1 In the same project (the networks don't have to be connected)

2 Google Cloud or on-premises clients must access the load balancer privately by being either in the same VPC network, in a peered VPC network, or in another network connected using Cloud VPN tunnels or Cloud Interconnect attachments (VLANs)

3 Supported if Premium Tier is used

Failover and availability

Feature Application Load Balancer Proxy Network Load Balancer Passthrough Network Load Balancer
Internal External Internal External Internal External
Automatic failover to healthy backends within same region
Automatic failover to healthy backends in other regions
(Only cross-region mode)

(Only global and classic4 modes)

(Only cross-region mode)

(Only global and classic4 modes)
Load balancer is resilient to zonal outages
Load balancer is resilient to regional outages
(Only cross-region mode)

(Only global and classic4 modes)

(Only cross-region mode)

(Only global and classic4 modes)
Behavior when all backends are unhealthy
info

info

info

info

info
(configurable)

info
(configurable1)
Configurable standby backends
info
(configurable)

info
(configurable2)
Connection draining on failover and failback
info
(configurable)

info
(configurable3)

1 When all the backends of a target pool-based external passthrough Network Load Balancers are unhealthy, traffic is distributed among all backends.

2 Target pool-based external passthrough Network Load Balancers use backup pools to support failover.

3 Target pool-based external passthrough Network Load Balancers don't support configuration of connection draining on failover.

4 Supported if Premium Tier is used

Monitoring

Feature Application Load Balancer Proxy Network Load Balancer Passthrough Network Load Balancer
Internal External Internal External Internal External
Byte count metrics
info

info

info

info

info

info
Packet count metrics
info

info
Round trip time (RTT) metrics
info

info
Request latency metrics
info

info

info
Connection count metrics
info

info
HTTP request count metrics
info

info

Logging

Feature Application Load Balancer Proxy Network Load Balancer Passthrough Network Load Balancer
Internal External Internal External Internal External
Log type
HTTP request and response attribute logs
info

info
Connection attribute logs
info

info

info

info
Log fields
HTTP request
info

global, classic
regional
String that explains the proxy response proxyStatus statusDetails
proxyStatus
TLS metadata between client and load balancer
info

(Only regional mode)
Connection attributes: 5-tuple, bytes/packets sent and received
info

info

info
VM instance details and GKE details
info

(Only regional mode)

info

info
Client VPC or location details
info

info
Network tier details
info
Labels describing the load balancer resource
info

global, classic
regional

info

info

info

info

Session affinity

For detailed information, see Session affinity.

For links to reference information, see Backend services.

Feature Application Load Balancer Proxy Network Load Balancer Passthrough Network Load Balancer
Internal External Internal External Internal External
Headers
(Only global and regional mode)
HTTP cookie
(Only global and regional)
Generated cookie
Client IP, no destination (1-tuple)
CLIENT_IP_NO_DESTINATION

info
Client IP, Destination IP (2-tuple)
CLIENT_IP
1 1
Client IP, Destination IP, Protocol (3-tuple)
CLIENT_IP_PROTO
1 1
Client IP, Client Port, Destination IP, Destination Port, Protocol (5-tuple)
CLIENT_IP_PORT_PROTO
1,2 1,2
None (5-tuple)
NONE
3 3

1 Setting session affinity is only meaningful if the protocol uses sessions—for example, TCP.

2 If the protocol does not have a concept of ports or if the packet does not carry port information (subsequent UDP fragments, for example), then a 3-tuple hash of the Client IP, Destination IP, and protocol is used instead.

3 If the protocol has a concept of ports and the packet carries port information, then None is a 5-tuple hash. If the protocol does not have a concept of ports or if the packet does not carry port information (for example, subsequent UDP fragments), then None is a 3-tuple hash of the Client IP, Destination IP, and protocol.

Load balancing methods

For detailed information, see the Backend services overview.

For links to reference information, see Backend services.

Feature Application Load Balancer Proxy Network Load Balancer Passthrough Network Load Balancer
Internal External Internal External Internal External
Balancing mode: connection
Balancing mode: rate (requests per second) 1 1
Balancing mode: backend utilization
(instance group backends only)
1 1
Configurable maximum capacity per backend instance group or NEG 1
global1
classic
regional
Circuit breaking 1
(Only regional mode)

(Only regional mode)
Weight-based load balancing
(Only global and regional modes)
1
Prefers region closest to client on the internet3
(Only global and classic4 modes)

(Only global and classic4 modes)
Prefers region closest to the load balancer3
(Only global and classic4 modes)

(Only classic4 modes)
Within zone/region load balancing policy
6

global5,6
classic5
regional5,6
5,6
global5,6
classic5
regional5,6

7

2

1 This feature is not supported with load balancers that use serverless NEG backends.

2 External passthrough Network Load Balancers use hash-based distribution among all backend services in the active pool when failover is configured, or among all backends in the region. Target pool-based load balancers also perform hash-based distribution among all instances in the target pool or backup pool.

3 When the closest region is at capacity or isn't healthy, the load balancer prefers next closest region.

4 Supported if Premium Tier is used

5 Round robin in a zone

6 Uses a load balancing locality policy to determine how traffic is distributed to instances or endpoints within the instance group or NEG

7 Hash-based distribution among all backends in the active pool when failover is configured, or among all backends in the region.

Routing and traffic management

Feature Application Load Balancer Proxy Network Load Balancer Passthrough Network Load Balancer
Internal External Internal External Internal External
HTTP or layer 7 request routing
info

info
Fault injection
info

(Only global and regional modes)
Configurable timeouts
info1

info

info

info
Retries
info1

info
Redirects
info

global
classic
regional
URL rewrites
info

global
classic
regional
Request and response header transformations
(configured on the URL map)

info

(Only global
and regional modes)
Traffic splitting
info

(Only global
and regional modes)
Traffic mirroring
info1

(Only global and regional modes)

(Only regional mode)
Outlier detection
info

(Only global and regional modes)
Retry failed requests
info

(Only global and regional modes)
Custom error responses
(Only global mode)

1 This feature is not supported with load balancers that use serverless NEG backends.

For traffic management features available with Traffic Director, see Traffic Director features: Routing and traffic management.

Autoscaling and autohealing

Feature Application Load Balancer Proxy Network Load Balancer Passthrough Network Load Balancer
Internal External Internal External Internal External
Managed instance group autoscaling based on load balancer serving capacity
Autohealing (native to managed instance groups and GKE)
Connection draining 1
1 This table documents autoscaling and autohealing features supported by backend service-based external passthrough Network Load Balancers. Target pool-based external passthrough Network Load Balancers don't support connection draining.

Security

Feature Application Load Balancer Proxy Network Load Balancer Passthrough Network Load Balancer
Internal External Internal External Internal External
Managed certificates
info

info

(Only global and classic mode)1
CORS
info

(Only global and regional)
Identity-Aware Proxy (IAP)
info
Google Cloud Armor
info

(Only global and classic mode)

info
SSL offload
(Only global and classic modes)1
SSL policies
(TLS version and cipher suites)

info

info

info
(Only global and classic modes)1
Frontend mutual TLS
info

info

1 Supported only if the load balancer is configured with a target SSL proxy

Special features

Feature Application Load Balancer Proxy Network Load Balancer Passthrough Network Load Balancer
Internal External Internal External Internal External
Cloud CDN
(Only global and classic2 modes)
External endpoints in internet NEGs as external backends for Cloud CDN
(Only global and classic2 modes)
Service Extensions callouts
info

(Only global and regional modes)
Internal DNS names
(Only regional mode)
Load balancer as next hop
info
Specify network interface of a backend VM
(Multi-NIC load balancing)

regional3

cross-region4
5 3 5 info 6
Custom request and response headers
(configured on the backend service)

(Only global and regional modes)
Automatic Service Directory registration (Preview)
info

info
Connection tracking policy
info

info1
Source IP-based traffic steering
info1
Supported with App Hub, which is in preview.
(Only regional mode)

(Only regional mode)

info

(Only regional mode)

info

info

1 These features are supported by backend service-based external passthrough Network Load Balancers. Target pool-based load balancers don't support these features.

2 Supported if Premium Tier is used

3 The backend VM's nic0 must be in the same network and region used by the forwarding rule.

4 The backend VM's nic0 must be in the same network used by the forwarding rule.

5 The load balancer only sends traffic to the first network interface (nic0), whichever VPC network that nic0 is in.

6 The load balancer only sends traffic to the first network interface (nic0) of the backend VM.

What's next

For detailed information about each load balancer, see the following: