How to Downgrade PHP Version on Ubuntu 24.04

Get PHP details

Before you downgrade PHP on Ubuntu 24.04, it’s smart to check your current PHP version and see which modules are installed.

First, list the current version of PHP by running the command below.

php --version
php -v

The command provided should produce an output similar to the example below. The currently installed version of PHP is [8.3.6].

PHP 8.3.6 (cli) (built: Dec  2 2024 12:36:18) (NTS)
Copyright (c) The PHP Group
Zend Engine v4.3.6, Copyright (c) Zend Technologies
    with Zend OPcache v8.3.6, Copyright (c), by Zend Technologies

Next, execute the command below to check which PHP modules have been installed.

dpkg --get-selections | grep -i php

The command above should output something similar to the one below. Here is a list of the PHP modules version currently installed on your system.

php8.3-bcmath					install
php8.3-cli					install
php8.3-common					install
php8.3-curl					install
php8.3-fpm					install
php8.3-gd					install
php8.3-imap					install
php8.3-intl					install
php8.3-ldap					install
php8.3-mbstring					install
php8.3-mysql					install
php8.3-opcache					install
php8.3-readline					install
php8.3-soap					install
php8.3-sqlite3					install
php8.3-xml					install
php8.3-xmlrpc					install
php8.3-zip					install
......
......

Having collected PHP and all its required modules, you can now downgrade to a version compatible with your environment.

Install older version of PHP

Installing an older PHP version on Ubuntu 24.04 is straightforward, letting you switch to a specific version like PHP 8.2 if needed.

To install PHP version 8.2 on Ubuntu, run the command below.

sudo apt install php8.2

If PHP 8.2 is unavailable in the default Ubuntu repositories, you can add a third-party PPA that provides this version.

Run the command below to add the repository.

sudo add-apt-repository ppa:ondrej/php
sudo apt update

Once the package index has been added and refreshed, try installing PHP 8.2 again.

After installing PHP 8.2, you’ll want to check the list of currently installed PHP modules. Make sure the right versions for PHP 8.2 are installed. You can get the list and run the command, replacing ‘version 8.3’ with ‘8.2’ for each module. This way, you’ll have both versions installed.

sudo apt install php8.2 php8.2-cli php8.2-commom php8.2-opcache php8.2-readline php8.2-bcmath php8.3-curl php8.2-gd					

Now you should have both [PHP 8.3] and [PHP 8.2] installed. However, your web server, such as Apache or Nginx, might still use PHP 8.3.

Switch PHP in Apache

To switch the PHP version for Apache, you’ll use the command below.

Disable the current PHP.

sudo a2dismod php8.3

Enable the PHP version you want to use.

sudo a2enmod php8.2

Restart Apache to apply the changes.

sudo systemctl restart apache2.service

Switch PHP in Nginx

If you’re using Nginx, you’ll need to update its configuration to point to the new PHP version after you downgrade PHP on Ubuntu 24.04.

    location ~ .php$ {
         include snippets/fastcgi-php.conf;
         fastcgi_pass unix:/var/run/php/php8.2-fpm.sock;
         fastcgi_param SCRIPT_FILENAME $document_root$fastcgi_script_name;
         include fastcgi_params;
    }

Restart Nginx and PHP-FPM after making the changes.

sudo systemctl restart nginx.service
sudo systemctl restart php8.2-fpm

That should do it!

Conclusion:

To sum up, downgrading your PHP version on Ubuntu 24.04 is quite manageable if you follow these steps. Here are the key points to remember:

• Check Current PHP Version: Always start by verifying your existing PHP version.
• List Installed PHP Modules: Assess which modules are currently installed to ensure compatibility with the older PHP version.
• Install Older PHP Version: Use the appropriate commands to 💿 install the required older version of PHP, such as PHP 8.2.
• Verify PHP and Modules: Ensure that the necessary PHP modules for the older version are correctly installed.
• Configure Web Server: Switch the PHP version as required depending on your web server (Apache or Nginx).
• Restart Services: Always 🔄 restart your web server and PHP-FPM after making configuration changes to apply the updates.

By following these steps, you can effectively manage your PHP versions and maintain the stability of your applications.