Caddy Technology Intelligence

What is Caddy?

Caddy is a powerful, enterprise-ready, open-source web server with automatic HTTPS. It's known for its simplicity, requiring minimal configuration while automatically obtaining and renewing TLS certificates from Let's Encrypt without any setup.

Written in Go, Caddy is a single binary with no dependencies. It supports HTTP/1.1, HTTP/2, and HTTP/3, reverse proxying, load balancing, and can serve static files or act as an API gateway. Its Caddyfile configuration format is designed to be human-readable.

Detection of Caddy indicates modern web server choice prioritizing ease of use and automatic security, commonly found in development environments, small to medium deployments, and anywhere automatic HTTPS with minimal configuration is valued.

Caddy Features

Automatic HTTPS: Let's Encrypt default. ZeroSSL backup. Auto-renewal. No configuration needed.

Reverse Proxy: Load balancing. Health checks. Header manipulation. WebSocket support.

HTTP/3: QUIC protocol. HTTP/2. HTTP/1.1. Automatic protocol selection.

Simple Config: Caddyfile format. Human-readable. JSON API. Dynamic configuration.

Static Files: File server. Compression. Range requests. Directory browsing.

Extensible: Plugin system. Custom modules. Go integration. Active ecosystem.

Caddy Use Cases

Simple Web Hosting: Static sites. Documentation. Landing pages. Personal websites.

Reverse Proxy: Application proxy. SSL termination. Load balancing. Backend routing.

Development: Local HTTPS. Quick setup. Hot reload. Testing environments.

Docker Deployments: Container proxy. Single binary. Small image. Easy configuration.

API Gateway: Request routing. Authentication. Rate limiting. API proxy.

File Sharing: Quick file server. Directory listing. Upload handling. Temporary sharing.

Caddy Configuration Examples

Caddyfile - Basic Site

# Automatic HTTPS for domain
example.com {
    root * /var/www/html
    file_server
    encode gzip
}

# Reverse proxy
api.example.com {
    reverse_proxy localhost:3000
}

# Load balancing
app.example.com {
    reverse_proxy backend1:8080 backend2:8080 {
        lb_policy round_robin
        health_uri /health
    }
}

JSON Configuration

{
  "apps": {
    "http": {
      "servers": {
        "srv0": {
          "listen": [":443"],
          "routes": [{
            "match": [{"host": ["example.com"]}],
            "handle": [{
              "handler": "file_server",
              "root": "/var/www/html"
            }]
          }]
        }
      }
    }
  }
}

Caddy Benefits

Automatic HTTPS: Zero configuration SSL. Let's Encrypt integration. Auto-renewal. Secure by default.

Simple Configuration: Human-readable Caddyfile. Minimal syntax. Easy to learn. Quick setup.

Single Binary: No dependencies. Easy installation. Cross-platform. Container friendly.

Modern Protocols: HTTP/3, HTTP/2. QUIC. TLS 1.3. Latest standards.

Open Source: Apache 2.0 license. Active development. Transparent. Community driven.

Performance: Go-powered. Efficient. Low resource usage. Fast startup.