Automatic HTTPS as default
TLS configuration is historically painful: obtain certificate, configure SSL directives, renew, restart server. Nginx/Apache require external automation (certbot). Caddy does something different: HTTPS automatic by default, transparent, with renewal.
The release
Caddy 1.0 is published in 2015 by Matt Holt. Caddy 2.0 is a full rewrite released on 4 May 2020. Written in Go, Apache 2.0 licence. Single binary ~25 MB, zero dependencies.
example.com {
reverse_proxy localhost:3000
}
api.example.com {
reverse_proxy localhost:8080
encode gzip
}These 5 lines do: obtain Let’s Encrypt certificate for example.com and api.example.com, configure HTTPS with HTTP/2 and HTTP/3, reverse proxy, gzip. Automatic renewal.
Features
- Automatic HTTPS — integrated ACME client (Let’s Encrypt, ZeroSSL)
- HTTP/3 (QUIC) natively supported
- Fluent reverse proxy
- Load balancing — round-robin, random, least-conn, IP hash
- Dynamic config — JSON API for reconfiguration without reload
- On-demand TLS — certificate at first hit for multi-tenant SaaS
- Modules — plugin system (auth, metrics, logging, hooks)
- Structured logging (JSON, slog)
- Prometheus metrics
- FastCGI (PHP-FPM, Python uWSGI)
Configuration formats
- Caddyfile — human-friendly DSL (see above)
- JSON — native API, more expressive
- Adapters — can import from nginx config, Consul, etc.
Versions
- 2.0 (May 2020) — rewrite
- 2.4 (March 2021) — HTTP/3 stable
- 2.5 (April 2022) — SNI improvements
- 2.6 (September 2022) — Go 1.18
- 2.7 (June 2023) — improved logging
- 2.8 (2024) — built-in Caddy metrics Prometheus
Competitors
- Nginx — industrial standard, faster under extreme load, verbose configuration, manual HTTPS
- Apache HTTPD — veteran, complex mod_ssl
- Traefik — similar auto-HTTPS philosophy, container/k8s oriented
- HAProxy — pure load balancer, TCP/HTTP
- OpenResty — nginx + Lua
Use cases
- Edge proxy for containerised apps
- Personal servers / homelab
- Dev environments with real HTTPS
- Multi-tenant SaaS with on-demand TLS
- Nginx replacement for teams valuing DX
In the Italian context
Caddy is used in:
- Italian web agencies for simple SSL hosting
- Homelab and self-hosting enthusiasts
- Startups wanting to avoid nginx configurations
- Edge gateway in front of Node/Python/Go apps
- Multi-tenant hosting (Italian B2B SaaS)
Often chosen as reverse proxy in front of Node.js or Python apps instead of Nginx.
References: Caddy 2.0 (4 May 2020). Matt Holt. Apache 2.0 licence. Written in Go. Automatic HTTPS via ACME (Let’s Encrypt, ZeroSSL). Native HTTP/3. Caddyfile DSL, JSON API.