How to Install PHP 8.1 for Nginx on Ubuntu

Introduction

PHP is one of the most widely used server-side programming languages for building dynamic websites and applications. Popular CMS platforms, such as WordPress, Magento, and Drupal, all run on PHP.

In this guide, we’ll walk you through how to install PHP 8.1 for Nginx on Ubuntu 20.04. We’ll cover every step in detail so even beginners can easily follow along. By the end, you’ll be able to configure, test, and run your PHP website hosting environment.

Steps to Install PHP 8.1 for Nginx

Step 1: Add the Ondrej PPA Repository

By default, Ubuntu 20.04 comes with PHP 7.4. To install the latest PHP versions, including PHP 8.1, we use the Ondrej PPA repository.

First, update your system and install dependencies:

sudo apt update
sudo apt upgrade
sudo apt install ca-certificates apt-transport-https software-properties-common

Now add the Ondrej PPA repository:

sudo add-apt-repository ppa:ondrej/php

Press ENTER when prompted.

Step 2: Install PHP 8.1 with Nginx

To set up PHP in Ubuntu with Nginx, install PHP-FPM (FastCGI Process Manager), which works best with Nginx.

sudo apt install php8.1 php8.1-fpm

Check if PHP-FPM is running:

sudo systemctl status php8.1-fpm

Now configure Nginx to process PHP files:

sudo nano /etc/nginx/sites-available/default

Update the server block:

location ~ \.php$ {
    include snippets/fastcgi-php.conf;
    fastcgi_pass unix:/run/php/php8.1-fpm.sock;
}

Restart Nginx:

sudo systemctl restart nginx

You have successfully installed PHP 8.1 for Nginx.

Step 3: Install PHP 8.1 Extensions

PHP extensions allow you to expand functionality for databases, caching, and more.
Example: Install MySQL extension:

sudo apt install php8.1-mysql

Install other extensions:

sudo apt install php8.1-cli php8.1-curl php8.1-xml php8.1-mbstring php8.1-zip

Step 4: Configure PHP 8.1

1. Edit the php.ini file to optimize performance:

sudo nano /etc/php/8.1/fpm/php.ini

2. Change these values:

upload_max_filesize = 32M
post_max_size = 48M
memory_limit = 256M
max_execution_time = 600
max_input_vars = 3000
max_input_time = 1000

3. Restart PHP-FPM:

sudo service php8.1-fpm restart

Step 5: Test PHP Processing

1. Check PHP version:

php -v

2. Create a test file:

sudo nano /var/www/html/info.php

3. Add:

<?php
phpinfo();
?>

4. Visit in your browser:

http://your-server-ip/info.php

You should see the PHP info page.

Step 6: Other Operations with PHP

1. Install Multiple Versions of PHP

sudo apt install php7.4 php7.4-fpm
sudo apt install php8.0 php8.0-fpm

2. Switch Between PHP Versions

sudo update-alternatives --config php

3. Check PHP Version

php -v

4. Uninstall a PHP Version. Example: remove PHP 7.4

sudo apt remove --autoremove php7.4
sudo add-apt-repository --remove ppa:ondrej/php

Conclusion

In this tutorial, we’ve learned how to install PHP 8.1 on Ubuntu 20.04 with Nginx. We covered everything from adding the repository, installing PHP-FPM, configuring Nginx, installing extensions, and testing PHP.

This setup is perfect for anyone who wants to install PHP on Ubuntu server, host websites using PHP for Linux, or even run multiple PHP versions. Whether you’re setting up a personal project or preparing for best PHP web hosting on Ubuntu, this guide has you covered.

Further Reading

• How to Install Nginx with HTTPS on Ubuntu 20.04
• How to Install LEMP Stack on Ubuntu 20.04