HAProxy vs Caddy: Which Reverse Proxy?

Quick Verdict

Caddy wins for self-hosting by a wide margin. Automatic HTTPS alone makes it the better choice for homelabs. Point Caddy at a domain name, write two lines of config, and you have a working reverse proxy with a valid SSL certificate. HAProxy is the more powerful load balancer — it handles extreme connection counts and offers advanced health checks and stick tables — but Caddy’s simplicity and built-in auto-TLS make it the practical choice for anyone running Docker containers on a single server.

Overview

Caddy (v2.10) is a modern web server and reverse proxy written in Go. Its headline feature is automatic HTTPS — it provisions and renews Let’s Encrypt certificates with zero configuration. Routes are defined in a Caddyfile, a minimal human-readable format where proxying a service takes two lines. Caddy also serves static files, supports HTTP/3, and exposes a JSON API for dynamic configuration.

HAProxy (v3.3) is a high-performance TCP/HTTP load balancer written in C. It powers some of the largest websites on the internet, including GitHub, Reddit, and Stack Overflow. Configuration lives in a single haproxy.cfg file with a structured syntax of global, defaults, frontend, and backend sections. HAProxy has no automatic HTTPS — you manage certificates externally and reference them in the config.

These tools solve different problems. Caddy prioritizes simplicity and developer experience. HAProxy prioritizes connection throughput and load balancing precision. For most self-hosters, simplicity matters more.

Feature Comparison

Feature	Caddy (v2.10)	HAProxy (v3.3)
Automatic HTTPS	Yes — zero config, enabled by default	No — external ACME client required
Configuration format	Caddyfile (minimal) or JSON API	haproxy.cfg (structured sections)
SSL certificate management	Built-in (Let’s Encrypt, ZeroSSL)	Manual — load certs from disk
Load balancing algorithms	Round robin, random, cookie hash, header hash	Round robin, least connections, source, URI, random, power-of-two
Health checks	Active and passive	Advanced — HTTP content matching, TCP checks, custom scripts
HTTP/3 (QUIC)	Yes	Not yet (planned)
API configuration	Yes — full JSON API on port 2019	No — config file only, reload via SIGHUP
Static file serving	Yes — full web server	No — proxy/load balancer only
WebSocket proxying	Automatic	Manual — requires option http-server-close tuning
Middleware/plugins	Modules via plugin system	ACLs and http-request rules
Stats dashboard	No built-in dashboard	Yes — real-time stats page with connection metrics
Docker labels support	Via caddy-docker-proxy plugin	No
TCP/UDP proxying	Layer 4 module (plugin)	Native — mature, battle-tested
Stick tables (session persistence)	Cookie-based hash	Advanced — IP, cookie, URL, custom keys with counters
Rate limiting	Via plugins	Native — stick tables with request rate tracking
License	Apache 2.0	GPL v2 (Community), HAProxy Technologies License (Enterprise)

Installation Complexity

Caddy setup for reverse proxying a service:

app.example.com {
    reverse_proxy myapp:8080
}

Two lines. HTTPS is automatic. No certificate config, no entry points, no backends section. Start the container, point DNS at your server, and Caddy handles the rest.

HAProxy setup for the same service:

global
    log stdout format raw local0

defaults
    mode http
    log global
    option httplog
    timeout connect 5s
    timeout client 30s
    timeout server 30s

frontend http_front
    bind *:80
    bind *:443 ssl crt /etc/haproxy/certs/app.example.com.pem
    http-request redirect scheme https unless { ssl_fc }
    default_backend app_backend

backend app_backend
    server app1 myapp:8080 check

That is 15+ lines before you even consider certificate provisioning. You still need to generate the SSL certificate externally (using Certbot, acme.sh, or similar), combine it into a PEM file, mount it into the container, and set up a renewal cron job. HAProxy does not manage certificates.

For self-hosting, this is not a close comparison. Caddy’s setup is measured in seconds. HAProxy’s is measured in minutes to hours, depending on your familiarity with its config format and certificate tooling.

Performance and Resource Usage

Metric	Caddy	HAProxy
Idle RAM	~20-40 MB	~15-30 MB
Under load RAM	~50-100 MB	~50-100 MB
Latency overhead	Very low	Extremely low (C, event-driven)
Max concurrent connections	High	Very high (designed for 100K+)
Docker image size	~40 MB (alpine)	~100 MB
Startup time	< 1 second	< 1 second

HAProxy is marginally more efficient under extreme load. Its C-based event-driven architecture is specifically designed for massive concurrency — tens of thousands of simultaneous connections with minimal overhead. Caddy’s Go runtime is fast but carries slightly more overhead per connection.

For a homelab running 5-30 services with a handful of concurrent users, this difference is invisible. Both proxies add sub-millisecond latency. The bottleneck is always the backend application, never the proxy. HAProxy’s performance advantage only materializes when you are serving thousands of requests per second across multiple backend servers.

Community and Support

Metric	Caddy	HAProxy
GitHub stars	60K+	5K+ (predates GitHub by 3 years)
First release	2015 (v1), 2020 (v2)	2001
Release cadence	Monthly	Quarterly (LTS branches)
Documentation	Excellent, concise	Comprehensive, detailed reference
Community	caddy.community forum	Mailing list, Discourse
Commercial support	Sponsorship tiers	HAProxy Technologies (Enterprise + ALOHA appliance)
Third-party tutorials	Growing rapidly	Extensive — 20+ years of content

HAProxy has a 14-year head start and powers critical internet infrastructure. Its documentation is thorough but assumes familiarity with load balancing concepts. Caddy’s documentation is notably beginner-friendly, with clear examples for every directive.

The self-hosting community skews toward Caddy and Traefik. Most homelab tutorials and Reddit discussions reference those tools. HAProxy content tends to target sysadmins managing production clusters. If you hit an issue with Caddy, you will find a self-hosting-relevant answer faster.

Use Cases

Choose Caddy If…

• You want automatic HTTPS with zero configuration
• You run a homelab with Docker containers on a single server
• You want the simplest possible reverse proxy config
• You also want to serve static files (Hugo, Astro, documentation sites)
• Memory is constrained (Raspberry Pi, small VPS)
• You want HTTP/3 support today
• You want an API for dynamic config changes without file editing
• You are new to reverse proxies

Choose HAProxy If…

• You need production-grade load balancing across multiple backend servers
• You proxy TCP traffic (databases, MQTT, game servers, mail)
• You need advanced health checks with HTTP content matching or custom scripts
• You need stick-table-based rate limiting and DDoS protection
• You need detailed real-time connection statistics
• You already manage HAProxy in production and know the config format
• Maximum throughput at extreme scale is a hard requirement

FAQ

Can HAProxy do automatic HTTPS like Caddy?

No. HAProxy has no built-in ACME client. You need an external tool like Certbot or acme.sh to provision and renew Let’s Encrypt certificates, then reference the PEM files in your HAProxy config. This is the single biggest usability gap between the two.

Is Caddy fast enough for production?

Yes. Caddy handles production traffic well and is used by companies serving millions of requests per day. The performance gap versus HAProxy only matters at extreme scale — thousands of concurrent connections with sub-millisecond latency requirements.

Can I use HAProxy and Caddy together?

Yes, and some setups do this. HAProxy handles TCP-level load balancing and routing at the edge, then forwards HTTP traffic to Caddy for automatic HTTPS and reverse proxying to backend services. This is overkill for a homelab but makes sense for multi-server deployments.

Which has better logging and monitoring?

HAProxy. Its built-in stats page shows real-time connection counts, error rates, backend health, and response times. Caddy logs requests but has no equivalent dashboard. For monitoring Caddy, you would add Prometheus and Grafana separately.

Final Verdict

Caddy is the right choice for self-hosting. The automatic HTTPS alone is reason enough — it eliminates certificate provisioning, renewal cron jobs, PEM file management, and an entire class of “my cert expired” outages. The Caddyfile is readable by anyone. Adding a new service takes two lines and zero restarts. For the typical self-hoster running Docker containers on a single server, Caddy does everything you need.

HAProxy is the right choice for a different problem. If you are load balancing traffic across multiple backend servers, proxying raw TCP connections, or need stick-table-based rate limiting, HAProxy is purpose-built for that work. It is lighter, faster under extreme load, and offers deeper traffic control. But those are enterprise concerns, not homelab concerns.

If you are reading this article trying to decide which reverse proxy to set up on your home server, the answer is Caddy.

Related

• How to Self-Host Caddy with Docker
• How to Self-Host HAProxy with Docker
• Traefik vs Caddy
• Traefik vs HAProxy
• Best Self-Hosted Reverse Proxies
• HAProxy vs Nginx
• Reverse Proxy Explained
• Docker Compose Basics