Overview

HAProxy brings reverse proxying, Layer 4 and Layer 7 routing, load balancing, and TLS termination into one tool. Its event-driven architecture and light multithreading on SMP machines are designed for demanding traffic, making it a strong candidate for very high-traffic websites. The project reports up to 2 million SSL requests per second and 100 Gbps of forwarded traffic on AWS Graviton2; that result is tied to that environment, not a performance guarantee for other deployments.

It supports TCP and HTTP applications, and recent versions include QUIC and HTTP/3 features. HAProxy 3.4 adds dynamic backends, HTTP/2 flood protections, ACME improvements, an OpenTelemetry filter, and experimental QMUX. These broaden routing, security, certificate, and observability options; QMUX's experimental status makes it less suitable where only established components will do.

Key features

Traffic management: Layer 4 and Layer 7 routing, load balancing, and TLS termination address common entry-point needs for TCP and HTTP services.
Security controls: Chroot, privilege drops, fork prevention, strict protocol validation, and checks for impossible states provide several defensive measures. They complement, rather than replace, the operator's responsibility for deployment and upkeep.
Release maintenance: Even-numbered LTS branches receive five years of maintenance; odd-numbered stable branches receive 12 to 18 months. That gives teams a longer maintenance path with LTS, while other stable branches require a nearer-term upgrade plan.
Downloads and integrations: The official site provides source repositories, release tarballs, snapshots, and versioned documentation. The 3.4 release notes include an OpenTelemetry filter and ACME certificate features such as DNS-01 challenges.

Pricing

The HAProxy Community Edition plan is free and includes a free load balancer with TCP and HTTP proxying. There is no free trial because the software is already free, and no managed service is offered. This fits teams willing to operate their own deployment; those wanting a vendor-managed load balancer should consider a different model. The project also points users to commercial support contracts and professional services from HAProxy Technologies.

Platforms

HAProxy Community Edition runs on Linux and is self-hosted. It ships with most mainstream Linux distributions and is often deployed by default in cloud platforms, which can make it a practical fit for teams already operating Linux infrastructure. It is not a managed service, so teams seeking an externally operated deployment should look elsewhere.

Who it's for

Choose HAProxy when you need TCP or HTTP proxying, load balancing, Layer 4 or Layer 7 routing, or TLS termination and have the capacity to manage Linux software. Its high-traffic focus and long LTS maintenance window can suit operators who value control over routing and upgrades. It is a weaker fit for teams that need a managed service or cannot take responsibility for branch maintenance.

Pros and cons

Pro: One free plan combines TCP and HTTP proxying with load balancing, Layer 4 and Layer 7 routing, and TLS termination.
Pro: Five-year maintenance for even-numbered LTS branches gives teams a longer supported path than the 12-to-18-month window for odd-numbered stable branches.
Pro: Defensive controls and newer protocol features support a broad range of front-door use cases.
Con: Self-hosting on Linux puts deployment and maintenance work on the operator.
Con: Experimental QMUX is not suited to teams that require every component to be established.

Alternatives

For a wider set of load balancing software or reverse proxy software, compare the relevant categories.

AWS Elastic Load Balancing is a paid service with a free tier for eligible new AWS customers, including 750 shared monthly hours for Classic and Application Load Balancers and 15 GB of Classic Load Balancer data processing. Consider it when that AWS free-tier allowance fits your needs.
MetalLB is a free, open-source Kubernetes load-balancing project; choose it when Kubernetes load balancing is the specific need.
VMware Workstation Pro is free for Windows or Linux hosts on 64-bit Intel or AMD PCs; consider it when that host-platform fit is the priority.
Array APV is a paid alternative.
F5 BIG-IP APM is a paid alternative with a free trial.
OpenELB is a free Linux, self-hosted alternative.
Hetzner Cloud Volumes is a paid alternative.
kube-vip is a free Linux, self-hosted alternative.

Verdict

HAProxy Community Edition is a strong choice for Linux teams that want free, self-hosted TCP and HTTP proxying with load balancing and routing control, particularly for high-traffic services. Its main reason to choose is the breadth of traffic-management capability without a license fee; look elsewhere if you need a managed service or do not want to own deployment and maintenance.

	Citrix ADC (now NetScaler)	HAProxy Community Edition
Free plan		Yes
Free trial		No
Paid from		Free
Platforms	api, Linux, self-hosted	Linux, self-hosted
Free plan	No	Yes
Managed service	No	No
Layer 7 routing	Yes	Yes
Layer 4 routing	Yes	Yes
Global traffic management	Yes
TLS termination	Yes	Yes

Citrix ADC (now NetScaler) vs HAProxy Community Edition

Citrix ADC (now NetScaler)

HAProxy Community Edition