Azure Application Gateway Vs Azure Load Balancer

Azure Application Gateway and Azure Load Balancer both distribute traffic across resources, but they operate at different layers of the network stack and serve different purposes.

Azure Load Balancer

• Operates at Layer 4 (transport layer) — works with TCP/UDP traffic
• Distributes traffic based on IP address and port, without inspecting content
• Extremely low latency, suited for high-performance, non-HTTP workloads
• Available in public and internal (private) configurations

Azure Application Gateway

• Operates at Layer 7 (application layer) — understands HTTP/HTTPS traffic
• Supports URL-based routing, SSL termination, and cookie-based session affinity
• Includes a built-in Web Application Firewall (WAF) for security
• Ideal for web applications that need intelligent, content-aware routing

Key Differences

• OSI layer — Load Balancer works at Layer 4; Application Gateway works at Layer 7
• Routing intelligence — Application Gateway can route based on URL path or hostname; Load Balancer cannot
• Security features — only Application Gateway includes WAF capabilities
• Best fit — Load Balancer for raw TCP/UDP performance; Application Gateway for HTTP-aware web traffic