HAProxy vs NGINX
HAProxy vs NGINX compared for 2026: HAProxy 3.4 LTS vs nginx 1.30 stable and 1.31 mainline, pure load balancer vs web server plus proxy, health checks, dynamic configuration without reloads, sticky sessions, rate limiting and stick tables, caching, HTTP/3 and QUIC, ACME certificates, observability, open-source vs HAProxy Enterprise and NGINX Plus (now NGINX Enterprise) gaps, release and support policies, with a clear pick per situation.
Quick Answer
HAProxy and NGINX both terminate TLS, proxy HTTP and TCP, and spread traffic across backends, and both are free and open source. They come at the job from opposite ends. HAProxy (GPLv2, with LGPL headers) is a dedicated TCP/HTTP load balancer and reverse proxy: it does not serve static files, but it gives you active health checks, stick tables for per-client tracking and abuse protection, a runtime API that can add servers and, since 3.4, whole backends without a reload, ACME certificate issuance (http-01, dns-01, dns-persist-01), a built-in Prometheus exporter and a small RAM cache. Its even-numbered branches are LTS with five years of fixes; 3.4 LTS shipped on 3 June 2026 and is supported to 2031-Q2 (latest 3.4.7, 14 October 2026). NGINX (2-clause BSD) is a web server first: static files, a disk-backed content cache, FastCGI and app hosting, plus reverse proxying, load balancing and a TCP/UDP stream proxy. Open-source nginx has gained sticky sessions (1.29.6), DNS re-resolution of upstreams (1.27.3), HTTP/2 to backends (1.29.4) and least_time balancing (1.31.0 mainline), but active health checks, API-driven upstream changes and the 200+ metric dashboard still sit in F5's commercial NGINX Plus, now sold as NGINX Enterprise. Latest: nginx 1.30.6 stable and 1.31.8 mainline. Pick HAProxy for a dedicated load-balancing tier in front of many backends. Pick NGINX when the same box also serves content or hosts the app.
Last updated November 13, 2026. Covers HAProxy 3.4.7 LTS (14 October 2026) and nginx 1.30.6 stable and 1.31.8 mainline (October 2026), using haproxy.org, docs.haproxy.org 3.4, HAProxy Technologies' community vs Enterprise table, nginx.org docs and CHANGES, and F5's NGINX Enterprise page, read in November 2026.
| Feature | HAProxy | NGINX |
|---|---|---|
| License | GPLv2 core with the LGPL on the exportable include files and an explicit OpenSSL linking exception; free for any use | 2-clause BSD; enterprise distributions and support from F5 |
| Primary Role | Dedicated TCP/HTTP reverse proxy and load balancer; its docs state it is not a static web server, not a forward proxy and does not modify request or response bodies | Web server first, plus reverse proxy, content cache, load balancer, TCP/UDP proxy and mail proxy |
| Protocols Proxied | TCP, HTTP/1.x, HTTP/2 and HTTP/3 (QUIC) on the frontend; HTTP/2 detected per side via ALPN; FastCGI to backends; QUIC to backends experimental since 3.3 | HTTP/1.x, HTTP/2, HTTP/3 (experimental), gRPC, FastCGI, uwsgi, SCGI, TCP and UDP via stream, mail (IMAP/POP3/SMTP); HTTP/2 to backends since 1.29.4 |
| Static Files & App Hosting | None by design; HAProxy chroots itself at startup and cannot serve files. Put NGINX, a CDN or an app server behind it | Core strength: static files, sendfile, gzip_static, byte ranges, and direct FastCGI/uwsgi/SCGI to application runtimes |
| Load-Balancing Algorithms | roundrobin (up to 4,095 active servers per backend), static-rr, leastconn, first, random (default since 3.3 is random(2)), URI, URL parameter, header and generic sample hash, with consistent hashing options | Round-robin, least_conn, ip_hash, generic hash (optionally consistent), random with two choices; least_time in open source since 1.31.0 mainline |
| Health Checks (Open Source) | Active and passive health checks in the free edition, including agent checks and extensible HTTP checks | Passive only (max_fails / fail_timeout); active health checks (ngx_http_upstream_hc_module) are commercial-subscription only |
| Runtime Changes Without Reload | Runtime API: add/del server, add/publish/del backend (3.4), update maps, ACLs and certificates; seamless reloads with persistent stats across reloads (3.3) | Graceful reload via HUP signal; DNS re-resolution of upstream servers (resolve) since 1.27.3; changing upstream membership through the API is commercial-subscription only; 1.31.5 mainline added a control API |
| Session Persistence | Cookie insertion and stick tables keyed on any sample (source IP, header, cookie, URL parameter); stick tables replicate between peers | sticky directive (cookie, route, learn) in open source since 1.29.6; zone sync of sticky state is commercial-only |
| Rate Limiting & Abuse Protection | Stick tables track request rates, connection counts and errors per client, URL or cookie; HTTP request rate limiting, queues for overload protection, traffic shaping | limit_req (leaky bucket, r/s or r/m) and limit_conn keyed on any variable; variable rates in limit_req are commercial-only |
| Caching | Small in-memory HTTP cache (total-max-size up to 4,095 MB, GET only, no persistent storage); docs recommend Varnish for an advanced cache | Disk-backed proxy_cache with keys and metadata in a shared memory zone (about 8,000 keys per MB); FastCGI/uwsgi/SCGI caches too |
| HTTP/3 & QUIC | QUIC/HTTP3 production-ready since 2.8; QUIC on the backend experimental in 3.3; QMux in 3.4 | ngx_http_v3_module since 1.25.0, documented as experimental support and not built by default |
| Automatic TLS (ACME) | Built-in ACME client (3.2+) with http-01, dns-01 and dns-persist-01 challenge types | ngx_http_acme_module, distributed as the nginx-module-acme package (and in NGINX Plus since 1.29.0); http-01 and tls-alpn-01 challenges |
| Observability | Detailed per-request logs, stats page, built-in Prometheus exporter (http-request use-service prometheus-exporter), OpenTelemetry in 3.4 | stub_status basic counters and access/error logs in open source; NGINX Plus/Enterprise API exposes 200+ real-time metrics |
| Extensibility | Lua (multi-threaded since 2.4) and SPOE (Stream Processing Offload Engine) agents for external processing | njs (ECMAScript-compatible) for HTTP and stream; third-party and dynamic modules; Perl module |
| UDP Load Balancing | Not in the community edition per HAProxy Technologies' feature table; UDP load balancing is listed as Enterprise-only | Yes, in open source via the stream module (for example DNS on 53/udp) |
| WAF & Bot Protection | Not in the community edition; HAProxy Enterprise adds its WAF, bot management, CAPTCHA and global rate limiting modules | Not in open source; F5 lists a separate WAF product for apps and APIs alongside NGINX Enterprise |
| Commercial Edition | HAProxy Enterprise plus HAProxy Fusion control plane: support, WAF, bot management, UDP, HA modules, map/ACL/TLS-key sync, SAML, geolocation, cloud images, RBAC via Fusion | NGINX Plus, presented by F5 as NGINX Enterprise (37.0 announced): active health checks, API-driven config without reloads, state sync, 200+ metrics, WAF option, NGINX One console |
| Pricing | Community: free. Enterprise and Fusion: no published price; quotes via HAProxy Technologies' request form 9/10 | Open source: free. NGINX Plus/Enterprise: no price on F5's product pages read; sales-led 8/10 |
| Kubernetes Ingress | HAProxy Kubernetes Ingress Controller (documented by HAProxy Technologies); HAProxy Technologies also publishes a migration path from ingress-nginx | F5 NGINX Ingress Controller and NGINX Gateway Fabric (Gateway API); not to be confused with the separate community ingress-nginx project |
| Release & Support Policy | Two branches a year; even branches are LTS for 5 years, odd branches stable for 12 to 18 months. LTS: 3.4 (to 2031-Q2), 3.2 (to 2030-Q2), 3.0 (to 2029-Q2) | Mainline (odd minor, new features) and stable (even minor, fixes) branches; 1.30 stable branch started 14 April 2026 |
| Latest Release (Nov 2026) | 3.4.7 LTS and 3.3.17 (14 October 2026); 3.5-dev12 (12 November 2026), 3.5 expected around 2026-Q4 | 1.31.8 mainline (21 October 2026); 1.30.6 stable (14 October 2026, five CVE fixes) |
HAProxy
HAProxy is an open-source TCP and HTTP reverse proxy and load balancer that has been in production since 2001. It focuses on one job, sitting in front of backends and deciding where each connection or request goes, and does it with health checks, stick tables, ACLs, a runtime API and very long-lived LTS branches. HAProxy Technologies sells HAProxy Enterprise and the HAProxy Fusion control plane on top of the same core.
Pros
- Built only for proxying and load balancing: active health checks, queuing, stick tables, ACL-based routing and per-client rate tracking are all in the free edition
- Runtime API adds and removes servers, updates maps and ACLs and, since 3.4, creates whole backends without a reload
- Even-numbered branches are LTS with five years of fixes (3.4 supported to 2031-Q2), backported by the same core team
- Native ACME client with http-01, dns-01 and dns-persist-01 challenges, plus a built-in Prometheus exporter
- Strict HTTP and TCP normalisation in front of fragile backends; QUIC/HTTP3 on the frontend and experimental QUIC to backends
- Shipped by most mainstream Linux distributions, with Alpine, Debian and RHEL-based Docker images linked from haproxy.org
Cons
- Not a web server: it will not serve static files or host applications, so you still need something behind it
- Caching is RAM-only and deliberately small (4,095 MB maximum per cache); HAProxy's own docs point heavy caching at Varnish
- UDP load balancing, the WAF, bot management, active/active HA modules and map/ACL sync across nodes are HAProxy Enterprise-only
- Configuration language is dense; ACLs, sample fetches and converters take time to learn
- No public price for HAProxy Enterprise or Fusion; it is sales-led
Best For
Dedicated load-balancing and edge tiers in front of many backends, TCP services (databases, MQTT, SMTP), and teams that want health checks, abuse protection and runtime changes without buying a commercial edition.
NGINX
NGINX is an open-source HTTP web server, reverse proxy, content cache, load balancer, TCP/UDP proxy and mail proxy, originally written by Igor Sysoev and now developed by F5. It is the default way many teams serve static files, front application servers and terminate TLS. F5 sells a commercial build, NGINX Plus, which its product pages now present as NGINX Enterprise.
Pros
- One binary serves static files, caches to disk, talks FastCGI/uwsgi/gRPC to apps and load-balances, so small stacks need nothing else
- Disk-backed proxy cache with keys in shared memory, suitable for real content caching rather than a small RAM cache
- Open-source nginx keeps absorbing former Plus features: upstream DNS re-resolution (1.27.3), sticky sessions with route and drain (1.29.6), least_time (1.31.0)
- TCP and UDP proxying through the stream module in the free build
- Huge ecosystem: distro packages, official nginx.org repositories, njs scripting, endless examples and config snippets
- 2-clause BSD licence is about as permissive as it gets for embedding and redistribution
Cons
- Active health checks, API-driven upstream changes without reloads, upstream state files, request queueing and slow_start are commercial-subscription only
- Built-in monitoring in the free build is stub_status: a handful of connection counters, not per-upstream metrics
- HTTP/3 is still labelled experimental and is not built by default (--with-http_v3_module)
- ACME support is a separate module package with http-01 and tls-alpn-01 challenges, no dns-01 listed
- Mainline and stable split means newer features (least_time, control API) land in 1.31 mainline before a stable branch
Best For
Serving static sites and assets, fronting application servers on the same host, disk-backed content caching, and small to mid-size stacks where one process should be web server, TLS terminator and load balancer at once.
Different starting points: load balancer vs web server
The single most useful fact in this comparison is in HAProxy's own introduction: HAProxy is a TCP proxy, an HTTP reverse proxy, a TLS terminator, a traffic regulator and a load balancer, and it is explicitly not a static web server. It chroots itself at startup and cannot read files to serve. NGINX describes itself the other way round: an HTTP web server first, then a reverse proxy, content cache, load balancer, TCP/UDP proxy and mail proxy. That difference drives everything else. With NGINX on a single VPS you can serve a React build, proxy /api to a Node or Python process, cache responses on disk and terminate TLS in one config file. With HAProxy you still need something to serve those files. In return, HAProxy's whole feature set points at the proxy job: queues that hold requests when backends are saturated, strict HTTP normalisation so malformed requests never reach fragile servers, per-request logs precise enough that its docs pitch it as a network troubleshooting tool, and stick tables that track arbitrary per-client counters. If you are choosing for a dedicated load-balancer tier, HAProxy fits the role more naturally. If you are choosing the one process that faces the internet on a small stack, NGINX does more of the work.
Where the open-source editions stop
Both vendors sell a commercial build, and the gaps sit in different places. On NGINX, the nginx.org module docs mark the line directive by directive. Active health checks (ngx_http_upstream_hc_module), changing upstream membership through the API module, the upstream state file, the queue directive and slow_start are still commercial-subscription only. But the line has moved a lot recently: DNS re-resolution of upstream servers and the upstream resolver arrived in open source in 1.27.3, sticky sessions plus the route and drain parameters in 1.29.6, and least_time balancing in 1.31.0 mainline. On HAProxy, HAProxy Technologies' own community-vs-Enterprise table shows the free edition already includes the Data Plane API, service discovery (DNS, Consul, AWS EC2), request rate limiting, caching, compression, OCSP stapling and Lua/SPOE customisation, and the runtime API handles server changes. What community lacks is UDP load balancing, technical support, the Fusion control plane, the WAF, bot management, CAPTCHA and SAML modules, geolocation, active/active and active/standby HA modules, map/ACL/TLS-ticket-key sync across nodes, and cloud images. In practice: health checks and runtime changes push NGINX users toward Plus; WAF, UDP and fleet management push HAProxy users toward Enterprise.
Runtime changes, reloads and service discovery
Container and autoscaling environments change backends constantly, so how each proxy absorbs that matters. Open-source NGINX reloads gracefully on a HUP signal: the master starts new workers with the new config and old workers finish their requests. Since 1.27.3 the server directive in an upstream block accepts resolve, so nginx re-resolves DNS names (including SRV records via the service parameter) without a reload, which covers a lot of Docker and Kubernetes service-name setups. Adding or modifying individual servers through an HTTP API, and keeping that state across restarts, remains an NGINX Plus feature. The 1.31.5 mainline added a control API; the docs read for this comparison do not yet describe what it can change, so do not plan around it. HAProxy's runtime API is broader in the free edition: add server and del server, map and ACL updates with versioned commits, certificate updates, and since 3.4 add backend from a default proxy followed by publish backend, so entire backends can be created, populated and removed without touching the config file. Seamless reloads have existed since 1.8, and since 3.3 stats persist across reloads. server-template with DNS resolvers and the Data Plane API are also in the community edition.
TLS, HTTP/3 and certificates
Both terminate TLS and both speak HTTP/2, but they are at different stages on HTTP/3 and automatic certificates. HAProxy declared QUIC production-ready in 2.8, added experimental QUIC towards backends in 3.3, and added QMux in 3.4. nginx's ngx_http_v3_module has existed since 1.25.0 but is still documented as experimental and is not compiled in unless you build with --with-http_v3_module (official packages may differ, so check your build). nginx security releases also keep touching HTTP/3: 1.31.7 and 1.30.6 on 14 October 2026 fixed an HTTP/3 request body injection bug among five CVEs, and 1.31.6 fixed an HTTP/3 buffer overflow. For certificates, HAProxy has a built-in ACME client since 3.2 that supports http-01, dns-01 and, in 3.4, dns-persist-01, a draft challenge that uses a static TXT record so renewals need no DNS API access. NGINX's ngx_http_acme_module ships as a separate nginx-module-acme package and lists http-01 and tls-alpn-01; there is no dns-01 option in its docs, so wildcard certificates still need an external client. Both support TLS Encrypted ClientHello in recent releases (HAProxy 3.3, nginx 1.29.4 with the OpenSSL ECH branch).
Support windows, upgrades and real-world cost
HAProxy's maintenance policy is unusually long and explicit. Two branches ship each year; even-numbered branches are LTS and get fixes for five years from the same developers who write new features, odd-numbered ones are maintained for 12 to 18 months. Today that means 3.4 (to 2031-Q2), 3.2 (to 2030-Q2) and 3.0 (to 2029-Q2) are all LTS, and 3.4.7, 3.3.17, 3.2.26 and 3.0.30 all shipped on 14 October 2026. HAProxy's docs suggest using your distribution's package if it follows the official cycle. NGINX runs a mainline (odd minor, features) and stable (even minor, fixes) split; 1.30 stable started on 14 April 2026, and features such as least_time and the control API are mainline-only for now. Money: both open-source editions cost nothing. Neither commercial edition has a public price on the pages read for this comparison; HAProxy Enterprise and Fusion are quoted through a request form, and F5's NGINX Plus page, now titled NGINX Enterprise, routes to sales. The practical cost difference is which features force the upgrade: active health checks and API-driven upstreams in NGINX, versus WAF, UDP and fleet management in HAProxy.
Verdict
Pick HAProxy when the box is a load balancer and nothing else: an edge or internal tier in front of many app servers, TCP services like databases or MQTT, or anywhere you need active health checks, stick-table rate tracking and runtime server changes without paying for a commercial edition. Stay on an LTS branch (3.4 to 2031-Q2, or 3.2 to 2030-Q2) and you get five years of backported fixes. Pick NGINX when the same server also serves static files, caches content to disk or hosts the application through FastCGI or a local proxy pass, which describes most single-VPS and small multi-node stacks. NGINX's free build now has sticky sessions and DNS re-resolution, but if you need active health checks or API-driven upstream changes in NGINX you are buying NGINX Plus (NGINX Enterprise), and at that point HAProxy's free edition usually covers the same ground. The common, sensible pattern at scale is both: HAProxy as the load-balancing tier, NGINX behind it serving content. If you need UDP load balancing on open source, NGINX's stream module does it and HAProxy community does not.