relayd vs Sozu
A side-by-side comparison of two self-hosted reverse proxy & gateways options — licensing, setup difficulty, resource needs, and what each one replaces.
| Feature | relayd | Sozu |
|---|---|---|
| Deploy effort | Read-the-docs project | Under-an-hour setup |
| Health score | 86 · Excellent | 88 · Excellent |
| Category | Reverse Proxy & Gateways | Reverse Proxy & Gateways |
| License | ISC | AGPL-3.0 |
| Language | C | Rust |
| Setup difficulty | Hard | Hard |
| Min. RAM | 32 MB | 128 MB |
| Deployment | bare-metal, source | docker, binary |
| GitHub stars | ★ 3,884 | ★ 3,734 |
| First released | 2006 | 2016 |
| Replaces | HAProxy, F5 BIG-IP | HAProxy, Nginx |
What are relayd and Sozu?
relayd
relayd is OpenBSD's daemon for relaying and load-balancing TCP connections, supporting application-layer filtering and SSL/TLS acceleration. It integrates closely with the pf packet filter.
- TCP load balancing
- Application-layer filtering
- TLS acceleration
- pf integration
Sozu
Sozu is an open-source HTTP reverse proxy written in Rust that can be reconfigured at runtime without dropping connections. It is built for safety and zero-downtime configuration changes.
- Hot configuration reload
- Memory-safe Rust core
- Zero-downtime changes
- Runtime control API
relayd vs Sozu: key differences
Relayd is written in C, while Sozu is built with Rust. Licensing differs — ISC for relayd versus AGPL-3.0 for Sozu. Relayd is the lighter option, starting around 32 MB of RAM against 128 MB for Sozu. Relayd is the more established project (first released 2006), while Sozu arrived in 2016. Sozu lists first-class Docker deployment; relayd does not.
Why pick each one
Choose relayd if…
- Tightly integrated with OpenBSD
- Very lightweight
Watch out for
- OpenBSD focused
- Terse configuration
Choose Sozu if…
- Released under the AGPL-3.0 license
- First-class Docker support for quick deployment
- Active community (3.7k GitHub stars)
- Written in Rust
Frequently asked questions
Is relayd or Sozu better?
Neither is universally better. relayd has the larger community; both share a hard setup difficulty, so the decision comes down to features and licensing.
Are relayd and Sozu free and open-source?
Yes. relayd is licensed under ISC and Sozu under AGPL-3.0. Both can be self-hosted at no software cost.
Can I run relayd and Sozu with Docker?
relayd: check the project docs for container support. Sozu: yes.
Which is lighter on resources, relayd or Sozu?
relayd has the smaller minimum footprint at 32 MB of RAM, compared to about 128 MB for Sozu. Real-world usage depends on library size, user count, and enabled features.