Upgrading from basic Load Balancer - Guidance

Important

On September 30, 2025, Basic Load Balancer will be retired. For more information, see the official announcement. If you are currently using Basic Load Balancer, make sure to upgrade to Standard Load Balancer prior to the retirement date. This article will help guide you through the upgrade process.

In this article, we'll discuss guidance for upgrading your Basic Load Balancer instances to Standard Load Balancer. Standard Load Balancer is recommended for all production instances and provides many key differences to your infrastructure.

Steps to complete the upgrade

We recommend the following approach for upgrading to Standard Load Balancer:

  1. Learn about some of the key differences between Basic Load Balancer and Standard Load Balancer.
  2. Identify the Basic Load Balancer to upgrade.
  3. Create a migration plan for planned downtime.
  4. Perform migration with automated PowerShell scripts for your scenario or create a new Standard Load Balancer with the Basic Load Balancer configurations.
  5. Verify your application and workloads are receiving traffic through the Standard Load Balancer. Then delete your Basic Load Balancer resource.

Basic Load Balancer SKU vs. standard Load Balancer SKU

This section lists out some key differences between these two Load Balancer SKUs.

Feature Standard Load Balancer SKU Basic Load Balancer SKU
Backend type IP based, NIC based NIC based
Protocol TCP, UDP TCP, UDP
Backend pool endpoints Any virtual machines or virtual machine scale sets in a single virtual network Virtual machines in a single availability set or virtual machine scale set
Health probe types TCP, HTTP, HTTPS TCP, HTTP
Health probe down behavior TCP connections stay alive on an instance probe down and on all probes down TCP connections stay alive on an instance probe down. All TCP connections end when all probes are down
Availability zones Zone-redundant and zonal frontends for inbound and outbound traffic Not available
Diagnostics Azure Monitor multi-dimensional metrics Not supported
HA Ports Available for Internal Load Balancer Not available
Secure by default Closed to inbound flows unless allowed by a network security group. Internal traffic from the virtual network to the internal load balancer is allowed. Open by default. Network security group optional.
Outbound Rules Declarative outbound NAT configuration Not available
TCP Reset on Idle Available on any rule Not available
Multiple front ends Inbound and outbound Inbound only
Management Operations Most operations < 30 seconds Most operations 60-90+ seconds
SLA 99.99% Not available
Global VNet Peering Support Standard ILB is supported via Global VNet Peering Not supported
NAT Gateway Support Both Standard ILB and Standard Public Load Balancer are supported via Nat Gateway Not supported
Private Link Support Standard ILB is supported via Private Link Not supported
Global tier (Preview) Standard Load Balancer supports the Global tier for Public LBs enabling cross-region load balancing Not supported

For information on limits, see Load Balancer limits.

Upgrade using automated scripts

Use these PowerShell scripts to help with upgrading from Basic to Standard SKU:

Next Steps

For guidance on upgrading basic Public IP addresses to Standard SKUs, see: