Add Dependencies
You must confirm that your site is compatible with the latest version of Drupal before you change the Drupal core version.
Review the steps below to confirm compatibility for your site's components.
Update to the latest version of MariaDB in all environments.
Use Upgrade Status to check the compatibility of all contributed modules and themes.
Convert your site to Composer if you plan to use the Upgrade Status module to assist in your upgrade.
Update all contributed projects and verify that they are compatible with the latest version of Drupal.
Update your custom code to make it compatible with the latest version of Drupal.
Update your core codebase to the latest version of Drupal.
Run
update.php
to update your PHP version.
You can find step-by-step instructions on the above items in Drupal's Upgrade documentation.