How to Change the PHP Version and php.ini Settings

Before upgrading: safe steps

1. Take a backup. Make sure you have a recent backup of your files and database.
2. Update your software. Bring WordPress core, plugins and themes to their latest versions; most compatibility fixes come with these updates.
3. Check compatibility. Plugins that haven't been updated in a long time and old hand-written code are the riskiest parts.
4. Test first if you can. Trying the new version on a test (staging) copy prevents surprises on the live site.
5. Go step by step. If you're coming from a very old version, going through the versions in between instead of jumping straight to the newest one makes problems easier to find.

Changing the PHP version in cPanel

In cPanel, the PHP version is changed per domain from the MultiPHP Manager screen:

1. Open MultiPHP Manager.
2. Tick your domain in the list.
3. Choose the new version from the PHP Version menu at the top right and click Apply.

Servers that use CloudLinux also have a Select PHP Version screen; from there you can manage not only the version but also the enabled PHP extensions (for example intl, imagick, redis) and some settings.

Changing the PHP version in DirectAdmin

In DirectAdmin, the PHP version is chosen in the domain's settings from the versions installed on the server. In the user panel's PHP version selection or Select PHP Version section, choose your domain and the version you want, then save. The versions you can choose are limited to those your provider has installed on the server.

Checking after the change

• Open and try the home page, inner pages, forms, the admin panel and the checkout steps, if you have them.
• Look at the error log in your control panel; warnings and errors that appear with the new version show up here.
• If something goes wrong, switch back to the old version from the same screen, update or replace the problematic plugin and try again.

If the site shows a white screen or a 500 error, the steps in our HTTP error codes article will help you find the problem.

Commonly changed php.ini settings

• post_max_size shouldn't be smaller than upload_max_filesize.
• The Allowed memory size exhausted error shows that memory_limit isn't enough, while errors on large file uploads show that the upload limits are too low.
• If large menus and forms with many fields don't save, increase max_input_vars.

In cPanel, you can change these settings from the MultiPHP INI Editor or the Select PHP Version → Options screen, and in DirectAdmin from the PHP settings section. Raise the values only as much as you need; very high limits can let a faulty script use up the server's resources.

PHP version on your own server (VPS)

On your own server, you usually connect PHP to the web server with PHP-FPM. On Ubuntu, the distribution's repository offers a single PHP version; if you need several versions, widely used third-party PHP repositories are the usual route. Each version runs as a separate service (for example php8.3-fpm), and in Nginx each site is pointed to the socket of the version it needs:

location ~ \.php$ {
    include snippets/fastcgi-php.conf;
    fastcgi_pass unix:/run/php/php8.3-fpm.sock;
}

You can see which version is used on the command line with php -v; the version used on the command line can differ from the one the web server uses. Each version has its own settings files (for example /etc/php/8.3/fpm/php.ini); restart the matching PHP-FPM service after making changes. We cover Nginx configuration in our How to install Nginx guide.

PHP at Nodesty

On Nodesty web hosting plans, you can choose your PHP version through cPanel or DirectAdmin and edit php.ini settings from the control panel; the LiteSpeed web server and CloudLinux isolation keep your PHP sites fast and stable. If you want to fully manage several PHP versions and PHP-FPM settings yourself, our AMD Ryzen 9 9950X VPS plans give you full root access. To speed up WordPress, take a look at our How to speed up a website guide too.