The PHP version of your website determines how fast, secure and compatible your site runs. In Plesk, you can change this in just a few clicks, without having to edit any files. In this article you’ll read why an upgrade is important, how to adjust the version step by step, and how to check that everything still works correctly afterward.
Why change the PHP version?
Outdated PHP versions eventually stop receiving security updates. This makes a website vulnerable to abuse, even if the rest of the hosting is well secured. Newer PHP versions are also faster, consume fewer server resources, and support modern features that many CMSs and frameworks now require.
WordPress, Drupal, Joomla and other CMSs often require a minimum (and sometimes also a maximum) PHP version. If you’re running a version no longer supported by your plugins or themes, you may get error messages or unexpected behavior. On LiteSpeed servers, such as those from Tandata, you’ll also notice extra speed gains with a current PHP version thanks to native support for the LiteSpeed PHP SAPI.
Changing the PHP version via Plesk
Changing the PHP version is done entirely through the Plesk interface, without needing the command line or technical knowledge.
Log in to Plesk
Go to your Plesk panel and log in with your account credentials. This is the central management hub for all your domains and settings.
Select the correct domain
Click on “Websites & Domains” and choose the domain for which you want to change the PHP version.
Open the PHP settings
Click on the “PHP Settings” tab. Here you’ll see all the PHP versions available on the server.
Choose the desired version
Select the version from the dropdown menu. Check your CMS or plugin documentation beforehand to see which version is required or recommended.
Adjust additional settings if needed
Think of memory limits, upload sizes, or active extensions. This is optional and mainly relevant for specific applications.
Save the change
Click “OK” or “Save”. Plesk will apply the new PHP version to your website immediately.
Checking and testing after the change
After changing the PHP version, check that everything continues to work correctly:
- Check the PHP version: place a file containing
<?php phpinfo(); ?>on your server and open it in the browser. Remove this file immediately after checking, as it displays sensitive server information. - Test functionality: check logging in, forms, uploads, and database connections.
- Check extensions: use phpinfo() to verify that required extensions such as curl, gd, and mysqli are active.
- Review error logs: consult the error logs in Plesk to detect hidden warnings that aren’t directly visible on the site.
Troubleshooting
If you get a white page or an error message after the change, this is usually a compatibility issue between your application and the new PHP version. In that case, simply switch back to the previous version using the same PHP settings in Plesk. Then check which plugin, module, or piece of code is causing the error, and update it before switching to the newer version again.
If you get stuck or are unsure which version best suits your website, check the knowledge base or contact support. If you’re considering switching to a hosting provider with modern server software, take a look at the options to switch to Tandata. For websites with accompanying business email or a new domain, you can arrange everything from the same Plesk panel.
Frequently Asked Questions
Can I upgrade to any PHP version?
Most current versions are available, but not every application supports every version. Very old versions such as PHP 5.6 are no longer offered for security reasons. Always check the system requirements of your CMS.
What happens if my website isn’t compatible with the new version?
You may get error messages or a white page. You can fix this by switching back to the previous PHP version in Plesk.
Is there downtime when changing the PHP version?
No, the change is applied immediately and your website remains accessible throughout the process.
How do I know which PHP version my CMS requires?
Consult the documentation of your CMS or plugin. It usually states a minimum and sometimes a maximum PHP version.
Do I also need to update my plugins after a PHP upgrade?
This is recommended. Outdated plugins are the most common cause of compatibility issues after a PHP upgrade.
Conclusion
Changing the PHP version in Plesk is a matter of just a few clicks, but it does require a brief check beforehand and a test afterward. This way you benefit from improved speed and security without any surprises on your website.