How to Install PHP 8.3 Alongside PHP 8.2 on Debian 12 with Nginx

By /

Running multiple PHP versions on the same Debian server is straightforward. Here’s how to add PHP 8.3 while keeping your existing 8.2 installations running.

Prerequisites

bash

sudo apt install -y lsb-release ca-certificates apt-transport-https software-properties-common gnupg2

Add the Sury PHP Repository

bash

curl -sSLo /usr/share/keyrings/deb.sury.org-php.gpg https://packages.sury.org/php/apt.gpg
echo "deb [signed-by=/usr/share/keyrings/deb.sury.org-php.gpg] https://packages.sury.org/php/ $(lsb_release -sc) main" | sudo tee /etc/apt/sources.list.d/php.list
sudo apt update

Install PHP 8.3

bash

sudo apt install php8.3 php8.3-cli php8.3-fpm php8.3-common
sudo apt install php8.3-mysql php8.3-curl php8.3-gd php8.3-mbstring php8.3-xml php8.3-zip

Set CLI Default (Optional)

bash

sudo update-alternatives --config php

Select option 3 for PHP 8.3.

Check What Your Sites Are Using

bash

grep -r "fastcgi_pass" /etc/nginx/sites-enabled/

Look for lines like fastcgi_pass unix:/run/php/php8.2-fpm.sock;

Migrate a Site to PHP 8.3

Edit your nginx site config and change:

nginx

fastcgi_pass unix:/run/php/php8.2-fpm.sock;

to:

nginx

fastcgi_pass unix:/run/php/php8.3-fpm.sock;

Then reload nginx:

bash

sudo systemctl reload nginx

Key Points

  • Both PHP versions run simultaneously as separate services
  • Existing sites stay on 8.2 until you update their nginx config
  • CLI default only affects command-line PHP, not your websites
  • Migrate sites one at a time when ready

Related Posts

Scroll to Top