Caddy is a modern, open-source web server written in Go with automatic HTTPS as its default behavior. It obtains and renews TLS certificates from Let's Encrypt without any configuration, making HTTPS setup effortless.

Should I use Caddy or Nginx?

Use Caddy if you want automatic HTTPS with zero configuration and simpler syntax. Use Nginx if you need maximum performance tuning, extensive module ecosystem, or you are already familiar with Nginx configuration.

Does Caddy support reverse proxy?

Yes. Caddy has built-in reverse proxy support with automatic HTTPS, WebSocket proxying, load balancing, and health checks. A reverse proxy in Caddy takes one line in the Caddyfile.

How much resources does Caddy use?

Caddy uses approximately 20-50 MB of RAM for basic web serving and reverse proxy. It runs comfortably on Raff's smallest $3.99/month tier alongside your application services.

How to Install Caddy Web Server on Ubuntu 24.04

In this tutorial, you’ll install Caddy on a Raff Ubuntu 24.04 VM, serve a static website, and verify automatic HTTPS in the browser.

Caddy is a modern web server that can serve websites and manage HTTPS certificates automatically. This tutorial installs Caddy from the official package repository, configures a simple static site, opens the required firewall ports, and verifies that HTTP redirects to HTTPS. Raff Technologies has supported 10,000+ VM deployments across its compute platform, and Raff Linux VMs can be provisioned in 60 seconds with NVMe storage and unmetered bandwidth.

This tutorial was tested on a Raff Ubuntu 24.04 VM. The browser verification used a domain pointed to the VM’s public IPv4 address.

Tested on Raff infrastructure by Aybars Altınyay, platform engineer at Raff Technologies.

Prerequisites:

A Raff Ubuntu 24.04 VM
SSH access with sudo privileges
A domain or subdomain pointed to your VM’s public IPv4 address
Ports 80/tcp and 443/tcp available on the VM
Basic familiarity with Linux terminal commands

📌 Note: Caddy needs a real domain or subdomain for public automatic HTTPS. Replace your-domain.com in this tutorial with your own domain.

Step 1 — Update system packages

Update the Ubuntu package index and install the required package tools:

Bash

sudo apt update
sudo apt upgrade -y
sudo apt install -y curl debian-keyring debian-archive-keyring apt-transport-https ufw

Verify that package upgrades are complete:

Bash

sudo apt list --upgradable

Expected output:

Text

Listing... Done

Step 2 — Install Caddy from the official repository

Add the Caddy repository key:

Bash

curl -1sLf 'https://dl.cloudsmith.io/public/caddy/stable/gpg.key' | \
  sudo gpg --dearmor -o /usr/share/keyrings/caddy-stable-archive-keyring.gpg

Add the Caddy stable repository:

Bash

curl -1sLf 'https://dl.cloudsmith.io/public/caddy/stable/debian.deb.txt' | \
  sudo tee /etc/apt/sources.list.d/caddy-stable.list

Make the keyring and repository file readable by APT:

Bash

sudo chmod o+r /usr/share/keyrings/caddy-stable-archive-keyring.gpg
sudo chmod o+r /etc/apt/sources.list.d/caddy-stable.list

Install Caddy:

Bash

sudo apt update
sudo apt install -y caddy

Verify the installed version and service status:

Bash

caddy version
systemctl status caddy --no-pager

Expected output includes:

Text

Active: active (running)

Step 3 — Configure UFW firewall rules

Allow SSH, HTTP, and HTTPS traffic:

Bash

sudo ufw allow 22/tcp
sudo ufw allow 80/tcp
sudo ufw allow 443/tcp
sudo ufw --force enable

Verify the firewall rules:

Bash

sudo ufw status numbered

Expected output includes:

Text

22/tcp    ALLOW IN
80/tcp    ALLOW IN
443/tcp   ALLOW IN

Step 4 — Point your domain to the Raff VM

Create an A record at your DNS provider:

Text

Type: A
Name: your-domain.com
Value: your-server-ip
TTL: Auto or 300

Replace your-server-ip with your Raff VM’s public IPv4 address.

Verify DNS from the VM:

Bash

dig +short your-domain.com

Expected output:

Text

your-server-ip

If DNS does not return your VM IP yet, wait for propagation before continuing.

Step 5 — Create a static website directory

Create a directory for the website:

Bash

sudo mkdir -p /var/www/caddy-demo

Create a test page:

Bash

cat <<'EOF' | sudo tee /var/www/caddy-demo/index.html
<!doctype html>
<html lang="en">
<head>
  <meta charset="utf-8">
  <title>Hello from Caddy on Ubuntu 24.04</title>
  <style>
    body {
      font-family: system-ui, sans-serif;
      max-width: 760px;
      margin: 80px auto;
      padding: 0 24px;
      line-height: 1.6;
    }

    code {
      background: #f2f2f2;
      padding: 2px 6px;
      border-radius: 4px;
    }
  </style>
</head>
<body>
  <h1>Hello from Caddy on Ubuntu 24.04</h1>
  <p>This static website is served by Caddy on a Raff Ubuntu 24.04 VM.</p>
  <p>HTTPS is active and managed automatically by Caddy.</p>
</body>
</html>
EOF

Set ownership for the Caddy service user:

Bash

sudo chown -R caddy:caddy /var/www/caddy-demo

Verify the file exists:

Bash

ls -l /var/www/caddy-demo/index.html

Expected output includes:

Text

index.html

Step 6 — Configure the Caddyfile

Back up the default Caddyfile:

Bash

sudo cp /etc/caddy/Caddyfile /etc/caddy/Caddyfile.bak

Open the Caddyfile:

Bash

sudo nano /etc/caddy/Caddyfile

Replace the file contents with:

Caddyfile

your-domain.com {
    root * /var/www/caddy-demo
    encode gzip
    file_server
}

Replace your-domain.com with your real domain or subdomain.

Validate the configuration:

Bash

sudo caddy validate --config /etc/caddy/Caddyfile

Expected output includes:

Text

Valid configuration

Reload Caddy:

Bash

sudo systemctl reload caddy

Verify that Caddy is still active:

Bash

systemctl status caddy --no-pager

Expected output includes:

Text

Active: active (running)

Step 7 — Verify the HTTPS static site

Open your site in the browser:

Text

https://your-domain.com

The test page should load over HTTPS.

Verify HTTPS from the terminal:

Bash

curl -I https://your-domain.com

Expected output includes either:

Text

HTTP/2 200

or:

Text

HTTP/1.1 200 OK

Verify that HTTP redirects to HTTPS:

Bash

curl -I http://your-domain.com

Expected output includes:

Text

308 Permanent Redirect

Step 8 — Verify Caddy end to end

Click the browser security icon next to the address bar and confirm that the connection is secure.

Caddy static website loading over HTTPS on Ubuntu 24.04

Verify the final service state from the VM:

Bash

systemctl is-active caddy
sudo ss -lntp | grep -E ':80|:443'
sudo caddy validate --config /etc/caddy/Caddyfile

Expected output includes:

Text

active
Valid configuration

End-to-end verification is complete when:

Caddy is active under systemd
Your domain points to the Raff VM
The static website loads over HTTPS
HTTP redirects to HTTPS
The browser shows a secure connection
Caddy listens on ports 80 and 443

Cleanup (Optional)

Use this section only when you want to remove Caddy, the demo website, TLS assets, repository files, and firewall rules from the VM.

⚠️ Warning: The following commands remove the Caddy site, local configuration, and Caddy-managed certificate data. Back up anything you need before proceeding.

Stop and disable Caddy:

Bash

sudo systemctl stop caddy
sudo systemctl disable caddy

Remove the demo website:

Bash

sudo rm -rf /var/www/caddy-demo

Remove Caddy packages:

Bash

sudo apt remove --purge caddy -y
sudo apt autoremove -y

Remove Caddy configuration, data, logs, repository file, and keyring:

Bash

sudo rm -rf /etc/caddy
sudo rm -rf /var/lib/caddy
sudo rm -rf /var/log/caddy
sudo rm -f /etc/apt/sources.list.d/caddy-stable.list
sudo rm -f /usr/share/keyrings/caddy-stable-archive-keyring.gpg

Remove public web firewall rules only if this VM no longer serves websites:

Bash

sudo ufw delete allow 80/tcp
sudo ufw delete allow 443/tcp
sudo ufw status numbered

Verify that Caddy is removed:

Bash

systemctl status caddy --no-pager

Expected output includes:

Text

Unit caddy.service could not be found.

Troubleshooting

Caddy cannot issue an HTTPS certificate

Cause: DNS is not pointing to the VM, ports 80 and 443 are blocked, or another service is already using those ports.

Fix:

Bash

dig +short your-domain.com
sudo ufw status numbered
sudo ss -lntp | grep -E ':80|:443'

Expected checks:

Text

dig returns your VM public IPv4 address
80/tcp is allowed
443/tcp is allowed
Caddy is the service listening on ports 80 and 443

If another web server is using ports 80 or 443, stop it before reloading Caddy:

Bash

sudo systemctl stop nginx
sudo systemctl stop apache2
sudo systemctl reload caddy

Only stop services that are installed and safe to stop on your VM.

The browser shows an insecure connection

Cause: You are using an IP address instead of a domain, DNS has not propagated, or certificate issuance has not completed.

Fix:

Bash

dig +short your-domain.com
sudo journalctl -u caddy --no-pager -n 80
curl -I https://your-domain.com

Expected output from the HTTPS check includes:

Text

200 OK

If DNS is correct and ports are open, wait one minute and refresh the browser.

Caddy fails to reload after editing the Caddyfile

Cause: The Caddyfile contains a syntax error.

Fix:

Bash

sudo caddy validate --config /etc/caddy/Caddyfile

Edit the Caddyfile:

Bash

sudo nano /etc/caddy/Caddyfile

Reload after validation succeeds:

Bash

sudo systemctl reload caddy

Expected output from validation:

Text

Valid configuration

The site returns 404

Cause: The Caddyfile root path does not match the website directory, or index.html is missing.

Fix:

Bash

ls -l /var/www/caddy-demo
sudo grep -n "root" /etc/caddy/Caddyfile

Expected output includes:

Text

index.html
root * /var/www/caddy-demo

Reload Caddy after fixing the path:

Bash

sudo systemctl reload caddy

The site returns 403

Cause: Caddy cannot read the website files.

Fix:

Bash

sudo chown -R caddy:caddy /var/www/caddy-demo
sudo chmod -R 755 /var/www/caddy-demo
sudo systemctl reload caddy

Verify again:

Bash

curl -I https://your-domain.com

Expected output includes:

Text

200 OK

Conclusion and next steps

You now have Caddy installed on a Raff Ubuntu 24.04 VM, serving a static website over automatically managed HTTPS. You also verified the browser security state, HTTP-to-HTTPS redirect behavior, and the active Caddy service. If you have not deployed your Raff VM yet, you can spin one up in 60 seconds at rafftechnologies.com.

Next: How to Set Up Caddy as a Reverse Proxy on Ubuntu 24.04

Guide: Firewall Best Practices for Cloud Servers

Guide: Choosing the Right VM Size for Your Workload

Install Caddy Web Server on Ubuntu 24.04

Prerequisites

How to Install Caddy Web Server on Ubuntu 24.04

Step 1 — Update system packages

Step 2 — Install Caddy from the official repository

Step 3 — Configure UFW firewall rules

Step 4 — Point your domain to the Raff VM

Step 5 — Create a static website directory

Step 6 — Configure the Caddyfile

Step 7 — Verify the HTTPS static site

Step 8 — Verify Caddy end to end

Cleanup (Optional)

Troubleshooting

Caddy cannot issue an HTTPS certificate

The browser shows an insecure connection

Caddy fails to reload after editing the Caddyfile

The site returns 404

The site returns 403

Conclusion and next steps

Put it into practice

Frequently asked questions