11 Top Load Balancers for 2025 (Cloud, Enterprise & Open Source)

If you're running production systems in 2025, your load balancer is one of the most critical components in the path. It decides how users reach your application, how resilient your services are to failure, and whether traffic gets absorbed or dropped under load.

Most engineers don’t think about their load balancer until it breaks and when it does, it takes the rest of your stack down with it. If one server is slow, it routes traffic there. If one region fails, it doesn’t failover. If it can't handle SSL, you end up terminating TLS inside your app. These are real pain points, and the wrong load balancer will surface them at the worst time, usually, during an incident.

The good news is there’s no shortage of powerful load balancing software in 2025. Whether you need global traffic routing across CDNs, L4 performance at the edge, or fine-grained L7 control for microservices, the options have matured. You can go managed, self-hosted, or hybrid. You can lean into automation, observability, and active health checks.

This guide breaks down the 13 best load balancers across commercial, open-source, and cloud-native ecosystems. It includes the tools we’ve seen, how they behave under real traffic, and which teams they’re actually built for.

Let’s get into it.

What Load Balancers Actually Do in a Modern Stack

A load balancer is the traffic cop for your application. It sits in front of your backend services and decides where each incoming request should go. That decision affects performance, availability, and user experience.

It can route based on the current load on each server, the health of your nodes, or even the contents of the request itself. A good load balancer will scale with your traffic, fail over cleanly, and stay invisible when everything is working. A bad one becomes the first root cause in your incident timeline.

There are different layers of load balancing. Layer 4 (L4) operates at the TCP or UDP level. It distributes raw connections. It is fast and efficient, often used when low latency is critical. Layer 7 (L7) operates at the HTTP level. It looks at headers, paths, cookies, or hostnames to route traffic with more intelligence. This is essential when you are running microservices, APIs, or user-facing applications that depend on smart routing.

Most modern stacks use both. You might terminate TLS at the edge on an L7 proxy, then forward to L4 balancers deeper in the network. Or you might use DNS-based load balancing at the global level and let your ingress controller do the rest.

In short, load balancing is not just about spreading traffic. It is about how you architect reliability, performance, and scale into your system.

Best Cloud Load Balancers in 2025

These are fully managed services offered by major cloud providers. They handle scaling, availability zones, and integration with your existing cloud infrastructure. If you're all-in on a particular cloud or want fewer moving parts, these are the options to look at.

1. AWS Elastic Load Balancer (ELB)

If your stack runs on AWS, ELB is the default load balancing layer. It is fully managed, deeply integrated, and production-proven across many types of workloads. You can choose from three flavors depending on your needs: Application Load Balancer (Layer 7), Network Load Balancer (Layer 4), and Gateway Load Balancer (service chaining for appliances).

Application Load Balancer (ALB) handles HTTP and HTTPS traffic. It supports routing based on hostnames, paths, headers, or query strings. This is ideal for modern web apps, REST APIs, and container workloads.

Network Load Balancer (NLB) operates at Layer 4 and is optimized for high-throughput, low-latency TCP and UDP traffic. It supports TLS passthrough and can handle millions of connections per second.

Gateway Load Balancer (GWLB) enables transparent traffic forwarding to third-party virtual appliances such as firewalls or intrusion detection systems, without needing to manage complex routing rules.

Pricing:

Pricing is usage-based across four flavors (ALB, NLB, GWLB, Classic), with charges per hour plus LCU/GB usage. In the US, ALB runs ~$0.024/hour plus ~$0.008 per LCU‑hour, NLB ~$0.0225/hour plus ~$0.006 per NLCU‑hour, and GWLB ~$0.0125/hour plus ~$0.004 per GLCU‑hour. A generous free tier includes 750 hours and 15 LCUs per month for 12 months.

Key Features:

• Built-in health checks and automatic failover across multiple AZs
• Native integration with EC2, ECS, EKS, and VPC
• TLS termination and SSL policy configuration
• Cookie-based session stickiness (for ALB)
• Support for WebSockets and HTTP/2 (ALB)
• Static IP and Elastic IP support (NLB)
• Flow logs via CloudWatch, real-time metrics via CloudWatch and X-Ray

Popularity and Market Share:

AWS ELB is the most widely used load balancer globally. As of 2025, it holds approximately 67% of the load balancer market share, dominating the managed cloud LB space. It is the default choice for most AWS workloads, especially in high-scale environments.

User Feedback (G2 Reviews):

On G2, AWS ELB holds an average rating of 4.6 out of 5 from over 160 reviews. Engineers consistently highlight its reliability and tight integration. One reviewer noted, "ELB helps you keep your workload up and running even when an issue occurs (like an instance failing). It is the most fire-and-forget load balancer we use."

Best For:

Use ELB when your infrastructure is running on AWS and you want built-in scalability and high availability without managing the load balancer yourself. ALB is great for HTTP-based apps with routing needs. NLB is best for TCP or TLS-heavy applications that need performance under pressure. GWLB fits use cases involving virtual appliances or security tools.

2. Google Cloud Load Balancing

Google Cloud Load Balancer is a fully managed, software-defined load balancer that supports both global and regional traffic distribution. It operates across multiple layers—L4 and L7—and supports HTTP(S), TCP, UDP, SSL, and even gRPC. All load balancers in GCP are tightly integrated into Google’s global infrastructure, the same backbone used by Gmail, Search, and YouTube.

It’s one of the few global L7 load balancers that offers true anycast. You get a single global IP address that routes each request to the nearest healthy backend, based on latency, health, and regional capacity. This reduces round-trip time and avoids manual DNS or geo-routing configurations.

Pricing:

GCP uses simple pricing per usage: you pay hourly for capacity and data processing. Exact rates depend on region and traffic type, with automatic billing for ingress, egress, and load balancer use. (Note: exact numeric values vary per region)

Key Features:

• Global anycast IP support with L7 and L4 routing
• Multi-protocol support: HTTP/HTTPS, TCP, SSL, UDP, gRPC, WebSockets
• Content-based routing (host, path, header, etc.)
• Autoscaling, auto-healing, and backend failover
• TLS termination and SSL certificate management
• Integrated Cloud CDN and Cloud Armor for security
• Observability with Stackdriver (now Google Cloud Monitoring) for logs and traces

Popularity and Market Share:Google Cloud Load Balancer is widely adopted in global, distributed applications that need fast, low-latency access. While AWS leads in market share, GCP’s load balancer is the top pick for companies already standardized on GCP services like GKE, Cloud Run, and Compute Engine.

User Feedback (G2 Reviews):Google Cloud Load Balancing has a rating of 4.5 out of 5 on G2. Users often call out its resilience under high traffic and seamless scaling. One reviewer wrote, "It handled massive traffic spikes without a hiccup. The integration with Cloud CDN and the ability to set up a global anycast IP with L7 routing is hard to beat." Advanced users also mention that while powerful, the configuration can be complex if you are not familiar with how GCP networking is structured.

Best For:Use Google Cloud Load Balancing if you are already running your workloads on GCP. It is especially well-suited for global services that need high throughput and low latency across regions. It also works well in Kubernetes environments using GKE, especially with built-in ingress controller support and autoscaling backends.

3. Azure Application Gateway

Azure Application Gateway is Microsoft’s Layer 7 load balancer. It is built for HTTP and HTTPS workloads and comes with integrated features like content-based routing, SSL offloading, and a built-in Web Application Firewall (WAF). If your infrastructure runs on Azure, it fits in naturally and handles most of the complexity for you.

It supports path-based routing, host header rules, multi-site hosting, and session affinity via cookies. These features are particularly useful for multi-tenant apps and microservice architectures. The Application Gateway scales automatically and supports zone redundancy across availability zones for fault tolerance.

SSL termination is handled at the gateway, which reduces CPU load on backend services. It can also do end-to-end SSL if you need to maintain encryption all the way to your services. The WAF runs in prevention or detection mode and uses the OWASP Core Rule Set for protection against common attacks.

Pricing:

Azure charges per gateway instance size and processed data volume. Small instances start at around $0.02/hour, scaling with capacity tiers; data processing is additional. WAF-enabled tiers cost more. (Official pricing is region-dependent)

Key Features:

• Layer 7 routing based on host, path, headers, or query strings
• Built-in Web Application Firewall (WAF) with OWASP rules
• SSL offloading and end-to-end SSL support
• Session affinity with cookie-based routing
• Autoscaling and zone redundancy
• Integration with Azure Kubernetes Service (AKS)
• Logging and metrics via Azure Monitor and Log Analytics

Popularity and Market Share:

Azure Application Gateway is widely used in enterprise environments that are already committed to Azure. While Azure’s overall LB share is smaller than AWS or GCP, it has strong adoption in industries with Microsoft-heavy stacks.

User Feedback (G2 Reviews):

It holds a 4.4 out of 5 rating on G2. Users appreciate its depth of features, especially the integrated WAF and support for complex routing rules. One engineer commented, “The ability to route based on paths and headers, and terminate SSL while keeping end-to-end encryption where needed, makes this one of the most flexible L7 balancers in a cloud environment.” Some also mention the configuration experience can be overwhelming for first-time users.

Best For:

Choose Azure Application Gateway if you are running in Azure and need intelligent HTTP(S) traffic management. It is especially useful for web apps, APIs, or AKS-based microservices where you need fine-grained routing and built-in WAF protection.

4. Cloudflare Load Balancing

Cloudflare Load Balancing is designed to run at the edge. It routes users across multiple data centers, cloud providers, or backend pools using real-time health checks and global Anycast. It also supports geo-routing, latency-based failover, and session affinity for stateful applications.

This is not just a DNS-based solution. Cloudflare’s global network of 250+ cities gives you an active load balancer that can make fast, proximity-aware decisions. You can load balance at the DNS layer, the HTTP layer, or both, depending on your architecture.

It integrates with Cloudflare’s broader security platform. You get built-in DDoS protection, a web application firewall, and bot filtering in the same pipeline as your traffic distribution. Health checks are performed at regular intervals, and if a pool fails, traffic is automatically rerouted with no manual action needed.

Pricing:

Global load balancing is a flat $5 per domain per month, plus $0.50 per million health‑checked requests. Geo-steering and priority pools are additional tiers. Bundling with Cloudflare CDN and WAF can adjust pricing.

Key Features:

• Global Anycast-based routing across multiple backends
• Active health checks with fast failover
• Session affinity and weighted load balancing
• Latency-based and geo-routing policies
• DNS-based and HTTP layer load balancing options
• Integrated WAF, DDoS protection, and caching
• Analytics, logs, and alerting through Cloudflare dashboard and APIs

Popularity and Market Share:

Cloudflare is used by 7,591,745 active websites and powers large portions of global internet traffic. Their load balancing product is widely adopted by teams running hybrid, multi-cloud, or edge-first applications.

User Feedback (G2 Reviews):

Cloudflare Application Security and Performance holds a 4.5 out of 5 rating on G2. Engineers call out its reliability and ease of use. One user said, “It accelerates real-time traffic and balances congestion without needing complex configuration. The failover is fast, and the UI gives you solid visibility.” Others appreciate how seamlessly it integrates with other Cloudflare tools.

Best For:

Use Cloudflare Load Balancing if you are routing traffic across clouds, CDNs, or global regions. It is especially effective when you want to combine performance, availability, and security into a single control point without adding infrastructure complexity.

5. IO River

IO River is a modern traffic control platform built for multi-CDN and multi-cloud environments. It helps you distribute traffic across multiple providers in real time. You can route based on performance, cost, availability, or any custom rule. Think of it as a meta-load balancer that sits above your existing infrastructure and makes smarter routing decisions at the edge.

Unlike traditional load balancers, IO River operates across vendors. If one CDN or cloud region is down or degraded, it shifts traffic to a healthy one automatically. It also provides edge logic, allowing you to run lightweight serverless functions right in the traffic flow. That means you can implement auth checks, redirects, headers, or other logic without touching your backend.

Pricing:

IO River uses a custom usage-based model priced at quote. It typically combines a base monthly fee with incremental charges per TB of traffic, number of edge endpoints, and active routing rules. (Contact sales for exact pricing.)

Key Features:

• Multi-provider traffic steering with real-time failover
• Performance and cost-based routing rules
• Built-in edge compute for request manipulation
• Dynamic health checks and global availability monitoring
• Centralized policy management for traffic, caching, and security
• API-first design with full automation support

Popularity and Market Share:IO River is a newer player in the edge and CDN orchestration space. While adoption is smaller compared to AWS or Cloudflare, it is growing fast among teams with hybrid and global architectures. It is often used to unify control across providers like AWS CloudFront, Cloudflare, Fastly, and others.

User Feedback:Users highlight IO River’s flexibility and the ability to reduce vendor lock-in. One early adopter shared, “We had multiple CDNs in place, and IO River gave us a single place to route traffic intelligently. It saved us from outages and helped optimize cloud egress costs too.” Although public reviews are limited, the platform is gaining traction with DevOps teams managing complex global delivery.

Best For:Use IO River if you are running services across multiple CDNs or clouds and want fine-grained control without building it yourself. It works especially well for global failover, traffic shaping, and cost optimization strategies in distributed systems.

6. F5 BIG-IP

F5 BIG-IP is one of the most advanced load balancing platforms used in enterprise data centers. It is more than a load balancer. It is a full-featured application delivery controller that supports L4 and L7 traffic management, SSL offloading, deep traffic inspection, and custom scripting with iRules.

You can deploy BIG-IP as a hardware appliance, virtual machine, or cloud instance. It supports high throughput and low latency, making it a top choice for mission-critical applications with strict uptime and performance requirements.

F5 gives you full control over traffic behavior. With iRules, you can inspect payloads, rewrite headers, redirect requests, and apply fine-tuned persistence logic. You also get built-in DDoS protection, application-level firewalls, and SSL visibility features to offload expensive compute from your backend services.

Pricing:

F5 offers both hardware and virtual editions, with pricing often based on throughput capacity or performance tier. A typical virtual package starts around $10k/year, plus support. Appliance pricing varies widely.

Key Features:

• Layer 4 and Layer 7 load balancing with intelligent routing
• iRules scripting engine for custom traffic logic
• SSL/TLS offloading and full proxy support
• Web Application Firewall (WAF), DNS load balancing, and DDoS defense
• Health checks and high availability clustering
• Real-time analytics and logging through F5 Telemetry

Popularity and Market Share:

F5 is a legacy enterprise vendor with strong presence in large on-prem and hybrid environments. It holds a sizable chunk of the high-performance ADC market and is known for its reliability under high load. It is frequently used by financial institutions, telecoms, and large SaaS providers.

User Feedback (G2 Reviews):

BIG-IP holds a 4.6 out of 5 rating on Gartner Peer Insights. Users highlight its depth and extensibility. One review says, “You can control everything about traffic. Once it’s in, you can shape it however you want. The interface takes getting used to, but it is incredibly powerful once set up.” Common praise includes strong vendor support and the ability to handle complex, multi-tenant routing scenarios.

Best For:

Use F5 BIG-IP when you need enterprise-grade performance and configurability. It is ideal for data centers and private clouds with strict security, compliance, and uptime requirements. If your architecture needs custom routing, deep packet inspection, or SSL visibility, BIG-IP delivers.

Best Open Source Load Balancers in 2025

Not every team needs a managed load balancer. Sometimes you need full control over routing logic. Sometimes you want something that runs inside your VPC with no external dependencies. And sometimes, you just want something battle-tested and cost-effective that you can inspect, extend, and run your way.

That is where open source load balancers come in. Let’s break down the top open source load balancers developers and operators trust in production today.

1. HAProxy

HAProxy is one of the most reliable and widely used open source load balancers in production today. It has been around for two decades, and for good reason. It is fast, stable, and incredibly configurable. You will find it running in front of high-traffic APIs, legacy applications, and container-based systems where engineers want full control over traffic handling.

HAProxy supports both Layer 4 and Layer 7 traffic. You can use it to load balance TCP, HTTP, HTTPS, and even gRPC with recent versions. It supports health checks, connection draining, sticky sessions, rate limiting, retries, and flexible routing based on headers, paths, cookies, or source IPs.

It also has native support for TLS termination, HTTP/2, and HTTP/3. The configuration syntax is powerful but takes time to learn. Once you are familiar with it, you can script and automate complex routing behavior that is hard to match in managed tools.

Pricing:

Open-source HAProxy is free. The Enterprise edition includes Fusion Control Plane and support under custom quote-based pricing. Organizations usually pay in the range of several thousand dollars per year based on deployment scale

Key Features:

• L4 and L7 load balancing with rich rule support
• Native support for TLS, HTTP/2, and HTTP/3
• Connection limits, rate limiting, retries, and stickiness
• Custom ACLs and flexible request routing
• Built-in health checks and failover
• CLI and Prometheus-compatible metrics endpoint
• Minimal resource footprint, suitable for edge or containerized use

Popularity and Market Use:

HAProxy is used by platforms like GitHub, Reddit, Stack Overflow, and many others. It is packaged into major Linux distros and available as a Helm chart or container image. According to GitHub, it has over 5.8k stars, and is actively maintained with regular feature releases.

User Feedback:

Engineers love HAProxy for its performance and stability. One common sentiment: “It has never crashed, and we’ve thrown a lot at it.” Another team lead said, “HAProxy lets us shape traffic exactly how we need. From splitting traffic between canary and stable, to dealing with partial failures, it has never been the bottleneck.”

Best For:

Use HAProxy when you want full control over routing, deep protocol support, and rock-solid stability. It is a great choice for bare metal, self-hosted environments, or when you are building ingress layers for high-performance services.

2. NGINX

NGINX is more than just a web server. It is one of the most popular open source reverse proxies and load balancers in use today. It powers some of the busiest sites on the internet and is trusted for its performance, reliability, and flexible configuration.

You can run NGINX as a Layer 7 load balancer for HTTP and HTTPS traffic. It handles path-based routing, header inspection, caching, SSL termination, and even WebSocket proxying. You can also use it at Layer 4 for TCP load balancing, although that requires a bit more manual setup.

NGINX configuration is simple and declarative. You define server blocks, upstream pools, and route rules in a readable way. It supports blue-green deployments, traffic splitting, and custom response handling. NGINX also handles gzip compression, rate limiting, request rewriting, and static file serving without breaking a sweat.

Pricing:

NGINX Plus is subscription-based at approximately $2,500 per instance per year. This includes active‑active HA, dynamic reconfiguration, metrics, and commercial support. Bulk and enterprise deals may lower cost per instance.

Key Features:

• Reverse proxy and L7 load balancer for HTTP/HTTPS
• Configurable L4 support for TCP/UDP proxying
• SSL termination, caching, and compression
• Sticky sessions, IP hash, round robin, and least connections
• Fast startup, low memory usage, and efficient connection handling
• Easily extendable with Lua scripts via OpenResty or NGINX Plus

Popularity and Market Use:

NGINX is used by companies like Netflix, Dropbox, and Airbnb. It has over 27.5k GitHub stars and is included in almost every Linux distro by default. It is also the foundation for many ingress controllers in Kubernetes environments.

User Feedback:

NGINX is known for being dependable under pressure. Engineers like how lightweight and easy it is to deploy. One comment we heard often: “It just works. We’ve run it on everything from Raspberry Pis to large-scale ingress layers, and it handles traffic consistently.” The learning curve is minimal, and it scales with your needs.

Best For:

Use NGINX when you want a lightweight, configurable load balancer that doubles as a reverse proxy. It is ideal for serving web applications, APIs, and content from edge nodes or as part of a Kubernetes ingress layer.

3. Traefik

Traefik is a modern, cloud-native load balancer and reverse proxy that was built for dynamic environments. If you are running Kubernetes, Docker Swarm, or Nomad, Traefik was designed with your workflow in mind. It automatically discovers services, configures routes, and reloads changes without downtime or restarts.

It supports Layer 7 routing with full TLS termination, path and header-based rules, and built-in support for Let’s Encrypt. It also handles TCP services, making it usable at Layer 4. What makes Traefik different is how tightly it integrates with service discovery. Instead of writing config files, you declare annotations or labels, and Traefik figures out the rest.

It also includes a built-in dashboard, Prometheus metrics, OpenTelemetry tracing, and support for middlewares like auth, rate limiting, redirects, and retries. Traefik v3 brings major performance improvements and support for gRPC, HTTP/3, and native Kubernetes Gateway API.

Pricing:

Open-source Traefik CE is free. Traefik Enterprise (Traefik Pilot) pricing is usage-based and quote-only. It includes developer support, advanced security, audit logging, and enhanced SLA.

Key Features:

• Dynamic L7 and L4 load balancing with service discovery
• Native integration with Kubernetes, Docker, ECS, and Consul
• TLS termination with automatic certificate management
• Built-in observability: dashboard, metrics, logs, and tracing
• Middleware stack for retries, redirects, auth, rate limiting
• Support for gRPC, HTTP/2, and HTTP/3

Popularity and Market Use:

Traefik is especially popular in the Kubernetes and DevOps community. It has over 55.6k GitHub stars, strong community support, and is widely used in small-to-mid-sized teams looking for automation and simplicity.

User Feedback:

Traefik is often praised for how hands-off it feels. One user said, “We didn’t write any config files. Once services were labeled in Kubernetes, everything just routed automatically.” It reduces manual ops and fits well in GitOps workflows. Some teams mention limited deep customization compared to HAProxy or NGINX, but most appreciate the tradeoff.

Best For:

Use Traefik when you are building cloud-native apps, especially with Kubernetes or Docker. It is ideal for teams that want dynamic routing, auto TLS, and tight integration with CI/CD pipelines and service discovery tools.

4. Envoy

Envoy is a high-performance proxy and load balancer originally built at Lyft, now a core component of many service meshes like Istio and Consul. It is designed for modern, cloud-native applications that need more than just basic routing. Envoy handles everything from traffic shaping and retries to advanced observability and mutual TLS.

It operates at both Layer 4 and Layer 7. It supports HTTP/1.1, HTTP/2, gRPC, and HTTP/3, along with TCP and TLS passthrough. Routing rules are defined via declarative configuration or the xDS API, which allows dynamic configuration updates from a control plane. This makes it ideal for service discovery and advanced load balancing in microservice environments.

Envoy comes with powerful observability features out of the box. You get detailed metrics, structured logs, distributed tracing, and full visibility into retries, failures, and upstream performance.

Pricing:

Envoy Proxy is an open-source project licensed under Apache 2.0 and is free to use with no licensing costs. You can self-host it across your infrastructure without fees. However, many teams opt for enterprise support provided by vendors like Tetrate and Solo.io. These support contracts typically start in the low five figures per year, depending on production environment scale and required SLAs.

Key Features:

• L4 and L7 proxying with HTTP/1.1, HTTP/2, HTTP/3, gRPC, and TLS
• Fine-grained routing, traffic splitting, retries, and circuit breaking
• mTLS, JWT auth, and rate limiting with extensions
• Advanced observability: metrics, tracing, access logs
• Native integration with Kubernetes, Istio, and other meshes
• Configurable via static files or dynamic xDS API

Popularity and Market Use:

Envoy is used by tech companies like Lyft, Google, and Airbnb. It is a CNCF graduated project with over 26.3k GitHub stars and strong momentum in the service mesh and edge proxy space. It is often embedded in larger platforms and commercial API gateways.

User Feedback:

Engineers call Envoy “production-grade from day one.” It is known for being fast, stable, and well-architected. One reviewer shared, “Envoy gives us complete control over how traffic flows through our platform, and it integrates cleanly into our observability stack.” The main challenge is the steep learning curve and complexity when used standalone.

Best For:Use Envoy when you are building or operating a service mesh, need gRPC-native support, or want advanced control over routing, auth, and telemetry. It is a strong choice when you care about performance and visibility, and are comfortable managing a more complex configuration model.

5. Seesaw

Seesaw is a Linux-based Layer 4 load balancer developed and open-sourced by Google. It is built specifically for large-scale environments that need high-performance network-level routing. Unlike HAProxy or NGINX, Seesaw focuses strictly on L4; TCP and UDP. It is often deployed inside private cloud or hybrid environments where simplicity, speed, and raw connection handling matter more than HTTP-level logic.

Seesaw uses IPVS (IP Virtual Server) under the hood and supports load balancing via direct server return (DSR), NAT, or tunneling. It is designed for high throughput, low latency, and minimal CPU overhead. It supports health checks, failover, and BGP announcements for high availability setups.

It is written in Go, designed to run on standard Linux servers, and is built with operational clarity in mind. Configuration is done via a YAML-like format, and it includes tools for managing pools, services, and backend health.

Pricing:

Seesaw is fully open-source and free to deploy. No licensing costs. You only bear infrastructure costs for your Linux servers and BGP setup.

Key Features:

• Layer 4 load balancing for TCP and UDP
• IPVS-based backend routing for performance
• Support for NAT, DSR, and IP-in-IP tunneling modes
• BGP support for announcing VIPs
• Active and passive health checks
• Simple operational model with minimal dependencies

Popularity and Market Use:

Seesaw is not as widely adopted as Envoy or NGINX, but it is trusted in performance-critical environments where HTTP-level routing is unnecessary. It has 5.7k+ GitHub stars, and while it does not have commercial support, it is often used in large-scale internal platforms.

User Feedback:

Engineers who use Seesaw value its simplicity and raw performance. One user said, “Seesaw does one thing well. It gives us fast, reliable TCP load balancing with full control over the network layer.” It is favored in scenarios where high throughput and control over routing modes are more important than application logic.

Best For:

Use Seesaw if you are building private cloud infrastructure or need a simple, fast, and reliable Layer 4 load balancer. It is especially effective for internal traffic, backend services, or situations where HTTP-level features are not required.

How to Choose the Right Load Balancer

Picking a load balancer is not about what has the most features. It is about what fits your architecture, your traffic profile, and your team’s operational model. Here is how to think about the tradeoffs:

If You’re All-In on a Cloud

• AWS ELB is your default. ALB for HTTP, NLB for TCP, GWLB for virtual appliances. Simple, integrated, and scales without much handholding.
• Google Cloud Load Balancer is best for global, latency-sensitive apps with multi-region failover. Strong integration with GKE.
• Azure Application Gateway is for deep HTTP routing, WAF support, and AKS environments where you want tight policy control.

If You Need Global Control Across Providers

• Cloudflare Load Balancing gives you global routing, real-time failover, and built-in DDoS protection. Works well for multi-cloud and edge.
• IO River is for teams routing across multiple CDNs or cloud providers. Ideal for egress optimization and fine-grained control at the edge.

If You’re Running On-Prem or Hybrid

• F5 BIG-IP is the enterprise standard. Full L4/L7 ADC with scripting, firewalls, and compliance baked in.
• Seesaw is for simple, high-throughput L4 balancing. Lightweight, fast, and runs well on Linux.

If You Want Full Open Source Control

• HAProxy is the most stable, configurable L4/L7 balancer out there. Great for performance and control.
• NGINX is lightweight and flexible. A solid reverse proxy that doubles as a smart load balancer.
• Traefik is perfect for Kubernetes or Docker teams. Dynamic routing, auto TLS, and easy observability.
• Envoy is your choice if you need service mesh-grade control. Great for gRPC, retries, circuit breaking, and mTLS.

Final Thoughts: What Actually Matters in 2025

Load balancers are no longer just about spreading traffic. They are now about how you enforce reliability, security, and performance at scale. Whether you’re balancing across pods, regions, or clouds, the right choice depends on how your architecture behaves under pressure.

There is no one-size-fits-all. You might use AWS ALB for your public APIs, HAProxy at the edge, and Envoy inside your mesh. That is normal. What matters is picking tools you can trust under load, that fail cleanly, and that fit your operational model.

The tools in this list are used by real teams, in real production systems, at real scale. Pick based on what your stack needs today, and how much control you want tomorrow.