Caddy vs OpenResty
A side-by-side comparison of two self-hosted reverse proxy & gateways options — licensing, setup difficulty, resource needs, and what each one replaces.
Caddy
Fast, multi-platform web server with automatic HTTPS
VS
OpenResty
Scalable web platform extending Nginx with Lua
| Feature | Caddy | OpenResty |
|---|---|---|
| Deploy effort | ≈5-minute setup | Under-an-hour setup |
| Health score | 99 · Excellent | 87 · Excellent |
| Category | Reverse Proxy & Gateways | Reverse Proxy & Gateways |
| License | Apache-2.0 | BSD-2-Clause |
| Language | Go | C |
| Setup difficulty | Easy | Hard |
| Min. RAM | 64 MB | 128 MB |
| Deployment | docker, binary, bare-metal | docker, binary, bare-metal |
| GitHub stars | ★ 76,004 | ★ 14,042 |
| First released | 2015 | 2011 |
| Replaces | Nginx, Apache | Nginx |
What are Caddy and OpenResty?
Caddy
Caddy is a powerful, extensible web server and reverse proxy written in Go that provides automatic HTTPS out of the box. Its simple configuration makes it popular for self-hosting.
- Automatic HTTPS by default
- Simple Caddyfile config
- Single binary
- Plugin ecosystem
OpenResty
OpenResty is a full-fledged web platform that bundles Nginx with LuaJIT and many libraries, enabling powerful programmable proxies and gateways. It is the foundation for several API gateways.
- Nginx plus LuaJIT scripting
- Programmable request handling
- Foundation for API gateways
- High performance
Caddy vs OpenResty: key differences
Caddy is written in Go, while OpenResty is built with C. Licensing differs — Apache-2.0 for Caddy versus BSD-2-Clause for OpenResty. Caddy is the lighter option, starting around 64 MB of RAM against 128 MB for OpenResty. OpenResty is the more established project (first released 2011), while Caddy arrived in 2015. Caddy has the considerably larger community, at 76,004 GitHub stars versus 14,042.
Why pick each one
Choose Caddy if…
- Zero-config TLS
- Easy to learn
Watch out for
- Fewer tuning knobs than Nginx
Choose OpenResty if…
- Very high performance
- Programmable with Lua
- Battle-tested Nginx core
Watch out for
- Lua knowledge required
- Config more complex than Nginx
Frequently asked questions
Is Caddy or OpenResty better?
Caddy is the stronger all-round pick: it has both the larger community and the simpler easy setup. Consider OpenResty if its specific feature set fits your needs better.
Are Caddy and OpenResty free and open-source?
Yes. Caddy is licensed under Apache-2.0 and OpenResty under BSD-2-Clause. Both can be self-hosted at no software cost.
Can I run Caddy and OpenResty with Docker?
Caddy: yes. OpenResty: yes.
Which is lighter on resources, Caddy or OpenResty?
Caddy has the smaller minimum footprint at 64 MB of RAM, compared to about 128 MB for OpenResty. Real-world usage depends on library size, user count, and enabled features.