Upgrading your website’s PHP version from 7.x to 8.5 is a multi-step process because it’s a major jump. PHP 8 introduces breaking changes, so careful planning is needed to avoid breaking your site. Upgrading means better security, improved performance, and avoiding obsolescence for your website.
Prerequisites
Access to cPanel or
Access to Funio Hub
SSH Access
Task completion: depends on expertise
Expertise: advanced
How to do it?
Log in to your cPanel.
In the Software section, choose Select PHP Version.
Take note of your current PHP version and the enabled PHP extensions.
Check if you are using a CMS (like Wordpress, Joomla, Drupal, etc.)
If you have a CMS, check what plugins and theme your site is using
Check the PHP requirements of the CMS, plugins and theme
Backup your Website
In cPanel open the Backup Wizard in the File section
Click Back up and follow the instructions
Audit Application Compatibility
PHP 8.4 introduces syntax and behavior changes. Verify if your CMS are compatible.
CMS minimun version: WordPress 6.4+, Joomla 4.4+, Drupal 10+, etc.
Plugins / Themes / Extensions: Must support PHP 8.4
Custom code: Check for deprecated functions
You can use this WordPress Plugin: PHP Compatibility Checker
You can manually review your code.
Common incompatibilities
create_function() removed
each() removed
Changes in type juggling and error handling
Deprecated functions and features
Recommended tools
PHPCompatibility (PHP_CodeSniffer)
CMS upgrade checkers
Test on a staging environment
PHP Compatibility Checker - WordPress Plugin
Recommended Upgrade Path
PHP 7.0 > 7.4 > 8.0 > 8.1 > 8.2 > 8.3 > 8.4 > 8.5
This minimizes fatal errors and simplifies debugging.
PHP 7.0 to 7.4
Fix legacy issues:
each() removed
create_function() removed
old MySQL functions (mysql_*)
Deprecated curly brace string offsets
Old array/string handling
PHP 7.4 to 8.0 (Biggest breaking change)
Strict type enforcement
Fatal errors instead of warnings
Engine error handling changes
Removed functions
Internal API changes
🔵 Goal: You should not have fatal errors in 8.0
PHP 8.0 to 8.1
Deprecated implicit nulls
New warnings
Return type enforcement
stricter internal function behaviour
🔵 Goal: Clean deprecation logs
PHP 8.1 to 8.2
Critical:
Dynamic properties deprecated
$obj->newProperty = 'value'; // deprecated
How to fix?
class MyClass {
public string $newProperty;
}🔵 Goal: No dynamic property warnings
PHP 8.2 to 8.3
Performance improvements
Engine optimizations
Minimal breaking changes
🔵 Goal: Stability
PHP 8.3 to 8.4
Performance upgrades
Memory handling improvements
Strict engine behaviours
🔵 Goal: Production hardening
PHP 8.4 to 8.5
Future compatibility
New features
Engine optimizations
Security improvements
🔵 Goal: Long-term stability
Troubleshooting and Common Issues
Enable error logs
Check for fatal errors in deprecated functions
Databases connections errors
Update CMS core
Update plugins/modules
Remove abandoned extensions
Remove outdated and unsupported plugins and themes
🔵