Envoy 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 | Envoy | Sozu |
|---|---|---|
| Deploy effort | Under-an-hour setup | Under-an-hour setup |
| Health score | 98 · Excellent | 88 · Excellent |
| Category | Reverse Proxy & Gateways | Reverse Proxy & Gateways |
| License | Apache-2.0 | AGPL-3.0 |
| Language | C++ | Rust |
| Setup difficulty | Hard | Hard |
| Min. RAM | 512 MB | 128 MB |
| Deployment | docker, kubernetes, binary | docker, binary |
| GitHub stars | ★ 28,983 | ★ 3,734 |
| First released | 2016 | 2016 |
| Replaces | Nginx, HAProxy | HAProxy, Nginx |
What are Envoy and Sozu?
Envoy
Envoy is a high-performance, open-source edge and service proxy designed for cloud-native applications and service meshes. It offers advanced load balancing, observability, and dynamic configuration.
- Service mesh data plane
- Dynamic xDS configuration
- Rich observability
- Advanced load balancing
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
Envoy vs Sozu: key differences
Envoy is written in C++, while Sozu is built with Rust. Licensing differs — Apache-2.0 for Envoy versus AGPL-3.0 for Sozu. Sozu is the lighter option, starting around 128 MB of RAM against 512 MB for Envoy. Envoy has the considerably larger community, at 28,983 GitHub stars versus 3,734.
Why pick each one
Choose Envoy if…
- Advanced load balancing
- Dynamic configuration API
- Deep observability features
Watch out for
- Steep learning curve
- Verbose YAML configuration
- Heavy for simple setups
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 Envoy or Sozu better?
Neither is universally better. Envoy has the larger community; both share a hard setup difficulty, so the decision comes down to features and licensing.
Are Envoy and Sozu free and open-source?
Yes. Envoy is licensed under Apache-2.0 and Sozu under AGPL-3.0. Both can be self-hosted at no software cost.
Can I run Envoy and Sozu with Docker?
Envoy: yes. Sozu: yes.
Which is lighter on resources, Envoy or Sozu?
Sozu has the smaller minimum footprint at 128 MB of RAM, compared to about 512 MB for Envoy. Real-world usage depends on library size, user count, and enabled features.