How To Install PHP (8.3, 8.2 or 7.4) on Debian 12

In this article, we will provide a step-by-step guide on how to install PHP on a Debian 12 system. We will specifically look into two different versions – PHP 8.3 and PHP 7.4, providing you with the flexibility to choose the version that suits your needs. PHP is a popular server-side scripting language often used for web development, which makes it an important installation for any web server.

Prerequisites

Its always a good practice to keep system packages up-to-date with the latest security patches and software updates. If any of the package are required to stick with specific version, You can exclude them from automatic upgrade. Now, execute the following commands to update Apt cache and then upgrade all system packages.

sudo apt update 
sudo apt upgrade 

Step 1: Add the SURY PHP PPA repository

The default Debian 12 repositories contains PHP 8.3 and PHP 7.4 packages, but not other versions like PHP 8.1, 7.3, 7.2 or 5.6. So we recommend to add a third-party repository, Ondřej Surý’s PHP repository, which provides up-to-date PHP packages. Run the following commands to add the repository:

sudo apt install -y apt-transport-https lsb-release ca-certificates wget 
wget -O /etc/apt/trusted.gpg.d/php.gpg https://packages.sury.org/php/apt.gpg
echo "deb https://packages.sury.org/php/ $(lsb_release -sc) main" | sudo tee /etc/apt/sources.list.d/php.list 

Then update the system to reflect the addition of the new repository.

sudo apt update 

Step 2: Installing PHP on Debian 12

As you have configured the required PPA on your system. Let’s install the required PHP version. You can also installed multiple versions on a single system.

• Installing PHP 8.3

To install PHP 8.3, execute the following command:

sudo apt install -y php8.3 

sudo apt install -y php8.2 

sudo apt install -y php7.4 

Step 3: Verify the Installation

You can check the installation using the same method as above:

php -v 

This should display the version of PHP that’s currently active on your system. If PHP 7.4 is correctly installed, it will reflect here.

Step 4: Switching PHP Versions (Optional)

If you have multiple versions of PHP installed, you can switch between them using the update-alternatives command. For example, to switch to PHP 7.4, you would use:

sudo update-alternatives --set php /usr/bin/php7.4 

To switch back to PHP 8.3, replace php7.4 with php8.2.

Conclusion

Congratulations! You now know how to install PHP 8.3, PHP 8.2 and PHP 7.4 on a Debian 12 system, and how to switch between the two versions. Remember, the version of PHP your server should run depends on your specific requirements and the compatibility of the web applications you plan to host. Always ensure to use supported and up-to-date versions of PHP for the best security and performance.