How to install WordPress with Caddy web server on Debian 9 (Stretch)?

Updated: 28 September 2026 · Applies to: Debian 12

Debian 9 and 10 are no longer supported, so this guide now uses Debian 12 (Ubuntu 24.04 works the same way).

Run WordPress on Debian 12 with Caddy (automatic HTTPS), PHP-FPM and MariaDB.

Before you start

• A VPS or dedicated server with a fresh Ubuntu 24.04 / Debian 12 or AlmaLinux 9 / Rocky Linux 9 installation, and root or sudo access.
• A domain or subdomain pointing to the server (an A record), if you want HTTPS.
• The system updated: apt update && apt upgrade or dnf upgrade.

Install Caddy

Ubuntu 24.04 / Debian 12 (official Caddy repository):

apt install -y debian-keyring debian-archive-keyring apt-transport-https curl
curl -1sLf 'https://dl.cloudsmith.io/public/caddy/stable/gpg.key' | gpg --dearmor -o /usr/share/keyrings/caddy-stable-archive-keyring.gpg
curl -1sLf 'https://dl.cloudsmith.io/public/caddy/stable/debian.deb.txt' | tee /etc/apt/sources.list.d/caddy-stable.list
apt update && apt install caddy

AlmaLinux 9 / Rocky Linux 9:

dnf install 'dnf-command(copr)'
dnf copr enable @caddy/caddy
dnf install caddy
systemctl enable --now caddy

Install PHP and MariaDB

apt install php-fpm mariadb-server php-mysql php-xml php-mbstring php-curl php-zip php-gd php-intl
mariadb-secure-installation

Create a database

mariadb -u root -p
CREATE DATABASE wordpress CHARACTER SET utf8mb4 COLLATE utf8mb4_unicode_ci;
CREATE USER 'wpuser'@'localhost' IDENTIFIED BY 'Strong-Password';
GRANT ALL PRIVILEGES ON wordpress.* TO 'wpuser'@'localhost';
FLUSH PRIVILEGES;
EXIT;

Download WordPress

cd /tmp && curl -O https://wordpress.org/latest.tar.gz
tar xzf latest.tar.gz
mkdir -p /var/www/example.com && cp -a wordpress/. /var/www/example.com/
chown -R www-data:www-data /var/www/example.com

Then open your domain in a browser and follow the installer: enter the database name, user and password you created, and create the admin account (do not call it "admin").

Caddyfile for WordPress

Edit /etc/caddy/Caddyfile:

example.com {
    root * /var/www/example.com
    php_fastcgi unix//run/php/php8.3-fpm.sock   # unix//run/php-fpm/www.sock on AlmaLinux/Rocky
    file_server
    encode gzip
}

Reload with systemctl reload caddy. Caddy gets and renews the HTTPS certificate automatically once the domain points to the server and ports 80 and 443 are open.

Open the firewall

ufw allow 80,443/tcp                                   # Ubuntu / Debian with UFW
firewall-cmd --permanent --add-service=http --add-service=https && firewall-cmd --reload   # AlmaLinux / Rocky

Note: Debian 12's PHP socket is /run/php/php8.2-fpm.sock; adjust the Caddyfile.