Overview
| Parameter | Nginx | Caddy |
|---|---|---|
| Language | C | Go |
| SSL/TLS | Manual (Certbot) | Automatic (ACME) |
| Architecture | Event-driven | Goroutines |
| Configuration | Text files | Caddyfile, JSON, API |
| HTTP/3 | Module support | Native support |
Nginx is an industry-standard web server and reverse proxy written in C. It focuses on high throughput and low resource consumption using an asynchronous architecture.
Caddy is a modern web server written in Go, designed for ease of use. Its primary advantage is the out-of-the-box automation of SSL certificate issuance and renewal via Let's Encrypt or ZeroSSL.
Performance
Nginx outperforms Caddy in extreme high-load scenarios. Due to its C codebase and lack of Garbage Collection (GC), Nginx consumes 2–10 MB of RAM in base mode. Benchmarks show Nginx handling 15–20% more Requests Per Second (RPS) with lower p99 latencies.
Caddy consumes more memory (30–50 MB+) due to the Go runtime. During traffic spikes, the Go GC can introduce additional latency. However, for 95% of business applications, the performance gap is negligible.
Configuration & complexity
Nginx uses an imperative configuration style. Setting up HTTPS requires installing Certbot, configuring cron jobs, and manually specifying certificate paths in the server block.
Caddy uses a declarative Caddyfile. A reverse proxy setup with automatic SSL looks like this:
example.com {
reverse_proxy localhost:8080
}Caddy also provides a full JSON API, allowing on-the-fly configuration changes without process restarts or file edits, which is critical for dynamic cloud environments.
When to choose what
- Choose Nginx for building CDNs, high-load media services, or when operating under strict RAM limits on edge nodes.
- Choose Caddy for rapid development, microservices, and SaaS platforms where users need custom domains with automatic HTTPS.
Cost / licensing
Nginx is distributed under the BSD-2 license. Nginx Plus is a commercial version offering advanced monitoring, WAF, and dynamic upstream configuration.
Caddy is licensed under Apache 2.0. All features, including the dynamic API and automatic TLS, are free in the open-source version.
Ecosystem & integrations
Nginx has a massive module ecosystem (Lua, OpenResty, njs), but adding them often requires recompiling the binary. Caddy uses a Go-based modular system. New plugins are added via the xcaddy tool, which builds a custom binary tailored to the user's needs.
Verdict
Nginx is the choice for infrastructure engineers who prioritize performance and granular control. Caddy is the tool for product teams prioritizing deployment speed and automated security workflows.