PHP version is one of the most impactful and most ignored aspects of WordPress performance and security. Many sites are still running PHP 7.4, which reached end-of-life in November 2022 — meaning no more security updates for a runtime that processes every WordPress page request.
The Performance Difference
PHP 8.x introduced the JIT (Just-In-Time) compiler, significantly improved the opcache, and reduced memory usage per request. Benchmarks vary by workload, but real-world WordPress sites typically see 10–30% faster PHP execution when moving from 7.4 to 8.2 or 8.3.
For an uncached page load that takes 800ms on PHP 7.4, that's a potential reduction to 560–720ms on PHP 8.3 with no code changes. For cached pages served directly by nginx, there's no PHP involved and the difference is zero — which is another reason to use a caching plugin.
The Security Difference
PHP 7.4 reached end-of-life in November 2022. PHP 8.0 in November 2023. PHP 8.1 reaches end-of-life in November 2025.
End-of-life means the PHP development team no longer publishes security fixes for that version. Vulnerabilities discovered after that date won't be patched. Sites running end-of-life PHP have known, unpatched vulnerabilities at the language runtime level.
This isn't theoretical. The PHP changelog includes multiple security fixes per release cycle. Running an EOL version means accumulating these unfixed vulnerabilities over time.
How to Check Your PHP Version
In your WordPress admin panel, go to Tools → Site Health → Info → Server. Your PHP version is listed there.
Alternatively, create a file called phpinfo.php in your web root containing <?php phpinfo(); ?>, visit it in a browser, and look for "PHP Version" at the top. Delete the file afterwards — leaving it accessible is a minor security risk.
WordPress Compatibility
WordPress 6.x officially supports PHP 7.2 through 8.3. Most modern WordPress plugins support PHP 8.0 and above. A small number of older or unmaintained plugins may have PHP 8.x compatibility issues — usually notices or warnings rather than fatal errors.
Before upgrading, check your active plugins against the WordPress plugin directory's compatibility information. Most plugins that are actively maintained will have addressed PHP 8.x compatibility.
Our PHP Support
We support PHP 7.4, 8.1, 8.2, and 8.3. You can switch your site's PHP version through the customer panel without downtime.
We recommend PHP 8.2 or 8.3 for all new WordPress installations. We notify customers running PHP versions approaching end-of-life before the deadline, not after.
Upgrading: A Cautious Approach
If you're upgrading from 7.4 to 8.x on an existing site, do it on a staging copy first. WordPress has a staging feature, or you can clone your site to a subdomain. Switch the PHP version, run through your site's key functionality, check for errors in the PHP error log, and then switch production once you've confirmed it works.
Most sites upgrade without issues. The ones that don't usually have a single outdated plugin that needs an update.