Every time someone opens your WordPress site, a lot happens on the server before the page appears. Most of that work is done by PHP, the programming language WordPress is written in.
PHP stands for "PHP: Hypertext Preprocessor." Yes, the name includes itself. It is a server-side language, which means it runs on your hosting server, not in the visitor's browser.
How Does PHP Work in WordPress?
When a visitor requests a page, PHP runs the WordPress code, fetches content from the MySQL or MariaDB database and builds a complete HTML page. The browser only receives that final HTML, never the PHP code itself.
Think of PHP as the chef in a restaurant kitchen. You never see the cooking; you only get the finished dish on your table. WordPress core, themes and plugins are all written mostly in PHP.
Why Does Your PHP Version Matter?
PHP keeps improving, and newer versions are usually faster and more secure. Older versions stop getting security fixes after a few years, which puts your site at risk.
You can check your version in Tools → Site Health → Info, under the Server section. Site Health also warns you when your PHP version is outdated. Here is our guide on how to know the PHP version in WordPress.
How to Update PHP for WordPress
- First, take a full backup of your site.
- Now, make sure your theme and plugins support the newer PHP version.
- Next, log in to your hosting control panel and open the PHP version settings.
- Here, choose the newer version and save the change.
- Finally, visit your site and check that everything works fine.
For more details, read our guide on how to update PHP in WordPress.
Test a PHP upgrade on a staging site first, if your host offers one. That way, an old plugin can't break your live site.
In short, PHP is the engine that runs your WordPress site. You don't need to learn it to run a blog, but knowing the basics comes handy. If you have any doubts about your PHP version, mention them in the comment box below.