caddy-l4 vs sslh
A side-by-side comparison of two self-hosted reverse proxy & gateways options — licensing, setup difficulty, resource needs, and what each one replaces.
| Feature | caddy-l4 | sslh |
|---|---|---|
| Deploy effort | Read-the-docs project | Under-an-hour setup |
| Health score | 85 · Excellent | 87 · Excellent |
| Category | Reverse Proxy & Gateways | Reverse Proxy & Gateways |
| License | Apache-2.0 | GPL-2.0 |
| Language | Go | C |
| Setup difficulty | Medium | Easy |
| Min. RAM | 64 MB | 32 MB |
| Deployment | binary, source | docker, bare-metal, binary |
| GitHub stars | ★ 1,780 | ★ 5,117 |
| First released | 2020 | 2008 |
| Replaces | HAProxy | HAProxy |
What are caddy-l4 and sslh?
caddy-l4
Caddy-L4 is an experimental application-layer-aware Layer 4 proxy app for the Caddy server, enabling TCP and UDP routing alongside Caddy's HTTP features. It allows protocol multiplexing on a single port.
- TCP and UDP proxying
- Protocol multiplexing
- Caddy integration
- Connection matchers
sslh
sslh is an applicative protocol multiplexer that lets HTTPS, SSH, OpenVPN, and other services share the same TCP port. It inspects the first bytes of a connection and forwards it to the right server.
- Share one port across protocols
- SSH and HTTPS on port 443
- Tiny resource footprint
- Probe-based routing
caddy-l4 vs sslh: key differences
Caddy-l4 is written in Go, while sslh is built with C. Licensing differs — Apache-2.0 for caddy-l4 versus GPL-2.0 for sslh. Sslh is the lighter option, starting around 32 MB of RAM against 64 MB for caddy-l4. Sslh is the more established project (first released 2008), while caddy-l4 arrived in 2020. Sslh has the considerably larger community, at 5,117 GitHub stars versus 1,780. Sslh lists first-class Docker deployment; caddy-l4 does not.
Why pick each one
Choose caddy-l4 if…
- Extends Caddy nicely
- Port multiplexing
Watch out for
- Marked experimental
- Requires Caddy knowledge
Choose sslh if…
- Released under the GPL-2.0 license
- Easy to set up — beginner-friendly
- First-class Docker support for quick deployment
- Mature project with 5.1k GitHub stars
Frequently asked questions
Is caddy-l4 or sslh better?
sslh is the stronger all-round pick: it has both the larger community and the simpler easy setup. Consider caddy-l4 if its specific feature set fits your needs better.
Are caddy-l4 and sslh free and open-source?
Yes. caddy-l4 is licensed under Apache-2.0 and sslh under GPL-2.0. Both can be self-hosted at no software cost.
Can I run caddy-l4 and sslh with Docker?
caddy-l4: check the project docs for container support. sslh: yes.
Which is lighter on resources, caddy-l4 or sslh?
sslh has the smaller minimum footprint at 32 MB of RAM, compared to about 64 MB for caddy-l4. Real-world usage depends on library size, user count, and enabled features.