An email from your host tells you your site's PHP version is outdated and will soon be disabled. The message is technical, the deadline is approaching, and you are not quite sure where to start to change your WordPress PHP version without causing an outage.
That worry is well founded: PHP is the language WordPress runs on, and changing versions can indeed reveal incompatibilities with your theme or some older plugins. That is exactly why this kind of update should never be done at random.
The good news is that the procedure is well understood and always follows the same logical order. With a bit of method, the vast majority of sites move from one PHP version to another with no incident visible to visitors at all.
Updating your WordPress PHP version without breaking anything means backing up the site, checking your theme and plugins for compatibility beforehand, then testing the change on a staging environment before applying it in production. Skipping one of these steps is what causes most blank screens after an update.
Why the PHP version matters so much for your site
PHP is regularly updated by its developers, with two main goals: performance and security. A recent PHP version runs WordPress faster, often significantly so, and fixes security flaws identified in earlier versions. Conversely, a PHP version that is too old eventually stops receiving any security patches at all, which makes it an exploitable weak point even if WordPress itself is perfectly up to date.
This is exactly why serious hosts enforce deadlines: they cannot keep running a PHP version that is no longer maintained indefinitely.
How to check which PHP version you are currently running
This information is generally found in the WordPress dashboard, under Tools > Site Health > Info, in the server section. It is also visible from your host's client area, often in the shared hosting or server settings. WordPress officially recommends using the latest stable PHP version available, or failing that, a version still actively maintained by its developers.
The risks of a poorly prepared PHP update
Changing PHP versions without checking beforehand can cause several kinds of problems:
- a critical error ("There has been a critical error on this website") that blocks the site from displaying
- a blank screen, with no visible error message to help you diagnose the issue
- broken functions in the theme or a plugin using code incompatible with the new version
- a dashboard you cannot access, while the public part of the site keeps working (or the other way around)
These symptoms are covered in more depth in our article on frequent WordPress errors, which covers the most common causes of this kind of breakdown.
The method for changing versions without breaking the site
Here is the order that most effectively limits the risk:
- fully back up the site (files and database) before touching anything, following our WordPress backup guide if needed
- check the PHP compatibility of your theme and every plugin on their official page
- update WordPress, the theme, and the plugins to their latest versions before touching PHP
- test the change on a staging environment if your host offers one
- temporarily enable debug mode to spot specific errors instead of a silent blank screen
- change the PHP version in production once the tests come back clean
- check the site in detail: main pages, contact form, cart if it is an online store, dashboard
This methodical approach turns a dreaded operation into a simple technical formality.
What to do if the site shows a critical error after the PHP update
If an error appears anyway, the first thing to check is the site's error log, which generally points to the exact file and line of code responsible. In most cases, the culprit is a plugin or theme using a PHP function that was removed in the new version. The fastest and safest fix remains to temporarily roll back to the previous PHP version while you fix or replace the faulty element, rather than leaving the site offline. Our dedicated page on a site broken after a WordPress update walks through what to do if you are already in that situation.
When to call in a professional
If your site relies on several older plugins, if you do not have a staging environment, or if a previous attempt already caused an error you could not solve, it is safer to hand this operation to a professional. The work typically includes a compatibility audit, a backup, the version change, and a full check of the site, without a prolonged interruption for your visitors.
Frequently asked questions
Can I roll back if the PHP update breaks my site? Yes, most hosts let you revert to the previous version in a few clicks from their client area, giving you time to fix the identified problem.
Which PHP version should I choose for my WordPress? WordPress recommends the latest stable version available. If your theme or an important plugin is not yet compatible, go with the most recent version they officially support, rather than the very latest one at all costs.
Does a PHP update affect my site's search ranking? Indirectly yes, and in a good way: a site made faster by a recent PHP version is generally viewed more favorably by Google, which factors loading speed into its ranking.
Is your host asking you to update PHP? Relax by Yumea handles the version change safely, with no risk of a critical error. Describe your situation, the diagnosis is free.