PHP 8.x brings significant speed improvements and handy language features such as named arguments, match expressions, and enums. Migrating mainly requires testing existing code for outdated functions and deprecated notices. With proper preparation, a staging environment, and the right PHP version in Plesk, the switch can usually be completed within an hour, without downtime for visitors.
What’s new in PHP 8.x
Since the introduction of PHP 8, a lot has changed compared to PHP 7. The most important additions that developers use daily:
- Named arguments: calling functions with argument names instead of a strict order, making code more readable.
- Match expression: a cleaner, type-safe replacement for the classic switch statement.
- Enums: a dedicated data type for fixed sets of values, useful for statuses and categories.
- Attributes: adding metadata directly in code instead of through separate comment blocks.
- Readonly properties: properties that can no longer be changed after initialization.
- Just-In-Time compiler (JIT): improves execution speed for certain computation-intensive scripts.
- Nullsafe operator (
?->): prevents errors when calling methods on potentially empty objects.
Each subsequent 8.x release adds smaller improvements, such as stricter type checks and better error messages, making bugs more visible earlier during development.
Why migrate now
Older PHP versions eventually stop receiving security updates. Websites running on an outdated version therefore face unnecessary risk of known vulnerabilities being exploited. In addition, newer PHP is noticeably faster, which has a direct impact on loading times and server load. Popular CMS systems such as WordPress, Magento, and Joomla almost always support PHP 8.x in their latest versions, and plugins or extensions increasingly require it as well.
Step-by-step plan for a safe migration
Make a full backup
Back up both files and database before making any changes, so you can always fall back on the current situation.
Check compatibility
Review the changelog of your CMS, plugins, and custom code for deprecated functions and breaking changes related to PHP 8.x.
Test on a staging environment
Set up a copy of your site on a test or staging environment and enable the new PHP version there via Plesk, without affecting the live site.
Check error logs
Visit important pages and functionalities and check the PHP error logs for warnings or fatal errors.
Switch live
Once everything runs stably on staging, change the PHP version for the live environment as well and immediately verify that everything functions correctly.
Common issues and solutions
When migrating to PHP 8.x, developers often encounter the same issues:
- Deprecated functions: some old functions have been removed or work differently. Replace these with the modern equivalent listed in the PHP documentation.
- Strict type checks: PHP 8.x is stricter about comparing and passing data types, causing previously unnoticed errors to surface now.
- Outdated plugins: not every extension or plugin has been updated for PHP 8.x. Look for an actively maintained alternative or update to the latest plugin version.
- Differences between PHP handlers: check that the correct PHP handler (for example via LiteSpeed) is active, as this can affect performance and compatibility.
If you’re unsure about an error message or whether your site is ready for migration, check the knowledge base or contact the support department. If you’re considering moving your hosting to a faster environment anyway, take a look at the options to switch to Tandata while keeping your settings.
Frequently Asked Questions
Can I run multiple websites with different PHP versions?
Yes, in Plesk you can set a specific PHP version per website or domain, allowing you to update and test sites independently of each other.
What happens if my code isn’t compatible with PHP 8.x?
Depending on the severity, you’ll get warnings or fatal errors. Always test on a staging environment first before moving the live site over.
Do I also need to update my CMS during a PHP upgrade?
In many cases, yes. Make sure your CMS, themes, and plugins are on the latest version, as developers implement compatibility with newer PHP versions in those updates.
Does a newer PHP version affect my email?
No, PHP versions have no effect on your email configuration. For business email with a good security score, check out business email.
Can I change the PHP version myself without a developer?
Yes, changing the PHP version is a simple setting in Plesk. However, testing your code for compatibility does require technical knowledge or help from a developer.
Conclusion
PHP 8.x offers clear speed improvements and modern language features, but requires a careful migration with staging tests and error log checks. With a good step-by-step plan and the right hosting environment, the switch can be achieved quickly and without surprises.