PHP is the language WordPress runs on, and your host decides which version your site uses. It’s easy to forget — until an old version stops getting security fixes, or a plugin update suddenly requires something newer.
How to check your PHP version
- In WordPress: Tools → Site Health → Info → Server.
- In your hosting panel: usually under a “PHP settings” or “PHP version” section.
- With WP-CLI:
wp --infoshows the PHP version in use.
Site Health will also warn you if your version is considered outdated.
Why the version matters
Each PHP version gets active support for a period, then security fixes only, then nothing. Running a version past its end of life means new security problems in PHP itself won’t be fixed on your server. The official schedule is on php.net’s supported versions page; WordPress lists its recommendation on its requirements page.
Newer versions also tend to be faster, and plugin authors gradually drop support for old ones — so staying current keeps updates possible.
What can break during an upgrade
Each major PHP version removes or changes some older features. Well-maintained plugins and themes keep up; problems usually come from:
- plugins that haven’t been updated by their authors for a long time,
- old premium plugins with expired licences,
- custom code in the theme or a snippets plugin,
- outdated themes, especially heavily customised ones.
How to upgrade safely
- Take a full backup.
- Update WordPress core, plugins and theme to their latest versions.
- Switch the PHP version on a staging copy and check key pages, forms and admin screens.
- Turn on the debug log on staging and look for deprecation warnings and errors.
- Fix or replace anything incompatible.
- Upgrade the live site, then check it again and watch the error log for a few days.
If something goes wrong
Most hosts let you switch back to the previous PHP version in a few clicks — the fastest way out of trouble. If the site shows a critical error, our guide to the WordPress critical error explains how to find the cause. Then fix the incompatibility and try again; staying on an unsupported version is only a delay.
Frequently asked questions
How do I check my WordPress PHP version?
Go to Tools → Site Health → Info and open the “Server” section. Your hosting control panel shows it too, and WP-CLI users can run wp –info.
Will upgrading PHP break my site?
It can, if a plugin, theme or custom code relies on something the newer version removed. That’s why the upgrade should be tested on staging first, with a backup and a way to switch back.
Which PHP version does WordPress recommend?
WordPress lists its recommended version on wordpress.org/about/requirements. As a rule, use a version that still receives security support from PHP and that your plugins support.
Can I change the PHP version myself?
Usually yes, from your hosting control panel. Most hosts let you switch back quickly if something goes wrong.