Step-by-Step Guide to Updating PHP Version on Nginx

To upgrade PHP on your Nginx server to version 8.4 or any other version (8.4 will be used in this blog), follow these steps. This assumes a Debian-based system (e.g., Ubuntu or Debian), as your CLI output indicates a Debian build.

1. Add the Ondřej Surý PHP Repository (if not already added)

This trusted PPA provides the latest PHP versions (including 8.4) for Ubuntu/Debian.

sudo apt install software-properties-common -y
sudo add-apt-repository ppa:ondrej/php -y
sudo apt update

(If you get a locale warning, prefix with LC_ALL=C.UTF-8 .)

2. Install PHP 8.4 FPM and Common Extensions

Install PHP-FPM for Nginx and extensions commonly needed for Laravel/web apps:

sudo apt install php8.4 php8.4-fpm php8.4-cli php8.4-mbstring php8.4-xml php8.4-curl php8.4-zip php8.4-gd php8.4-mysql php8.4-bcmath php8.4-intl -y

This installs co-existable versions—your existing older PHP remains unless removed.

3. Enable and Start PHP 8.4 FPM

sudo systemctl enable php8.4-fpm
sudo systemctl start php8.4-fpm
sudo systemctl status php8.4-fpm  # Verify it's active

4. Update Nginx Configuration to Use PHP 8.4 FPM

Edit your site's Nginx config file (commonly /etc/nginx/sites-available/default or /etc/nginx/sites-available/your-site.conf).

Find the PHP processing block (usually location ~ \.php$ {}) and change the fastcgi_pass line to the 8.4 socket:

location ~ \.php$ {
    include snippets/fastcgi-php.conf;
    # Or include fastcgi_params;
    fastcgi_pass unix:/run/php/php8.4-fpm.sock;  # This is the key change
    fastcgi_param SCRIPT_FILENAME \(document_root\)fastcgi_script_name;
    include fastcgi_params;
}

• The socket path is typically /run/php/php8.4-fpm.sock (confirm with ls /run/php/).

• If using a port instead (rare), it would be 127.0.0.1:9000 or similar—check /etc/php/8.4/fpm/pool.d/www.conf.

Save the file, then test and reload Nginx:

sudo nginx -t  # Test config
sudo systemctl reload nginx

5. Verify the Change

Create or edit a phpinfo.php file in your web root (e.g., /var/www/html/phpinfo.php):

<?php phpinfo(); ?>

Access it in your browser (e.g., http://your-server-ip/phpinfo.php). It should show PHP Version 8.4.16 (or similar) and Server API as FPM/FastCGI.

Delete this file afterward for security.

6. Optional: Clean Up Old PHP Version

If you no longer need the previous version (e.g., 8.3):

sudo apt purge php8.3*  # Adjust version as needed
sudo apt autoremove

Restart services afterward.

Your Laravel app should now load without the Composer platform warning, as the web runtime matches the required >=8.4.0.

If issues persist (e.g., 502 errors), check logs:

sudo tail -f /var/log/nginx/error.log
sudo journalctl -u php8.4-fpm

Thank you

I hope you found this helpful ✨