A significant share of WordPress sites are running on PHP versions that reached end of life years ago. That means no security patches, no performance improvements, and growing incompatibility with modern plugins and themes. Updating PHP is one of the highest-value, lowest-effort improvements you can make, and it is something many site owners overlook entirely because it happens below the WordPress interface.
PHP is the language WordPress is written in. Every page request on an uncached WordPress site involves PHP parsing template files, executing plugin logic, and querying the database. The speed of that PHP execution depends heavily on the PHP version running on the server.
PHP 8.x is meaningfully faster than PHP 7.4 for WordPress workloads. Benchmarks consistently show 15–40% faster execution time depending on the workload complexity, plugin stack, and site configuration. PHP 8.0 introduced JIT (Just-In-Time) compilation, which can accelerate compute-heavy operations. PHP 8.1 and 8.2 added further performance improvements including fibers, intersection types, and readonly properties that well-coded plugins take advantage of. PHP 8.x also improves opcache efficiency, the bytecode cache that prevents PHP from re-parsing files on every request, which is the single most impactful internal caching mechanism for WordPress.
In practical terms, moving from PHP 7.4 to PHP 8.2 on a moderately complex WordPress site often reduces TTFB on uncached pages by 50–150ms. On a site receiving thousands of daily visitors, that compounds into meaningful server load reduction and improved user experience.
Performance matters, but security is the more urgent reason to update. PHP versions follow a defined support lifecycle. Each version receives active development for two years, then enters security-only maintenance for an additional year, then reaches end of life, no more patches of any kind, including for actively exploited vulnerabilities.
PHP 7.4 reached end of life in November 2022. PHP 8.0 reached end of life in November 2023. Running either version means your server's PHP environment has known, publicly documented security vulnerabilities that will never be patched. WordPress core updates, plugin updates, and server firewalls cannot fully compensate for running an EOL PHP runtime. Any attacker who specifically targets PHP-level vulnerabilities has an unpatched attack surface on your server regardless of how well you maintain everything above it.
As of 2025, PHP 8.2 and 8.3 are actively maintained. PHP 8.1 is in security-only mode. The correct target is PHP 8.2 or 8.3, both receive active development and security patches, and both are supported by all major WordPress plugins and themes that are actively maintained.
In WordPress, go to Tools > Site Health and click the Info tab. Under the Server section, you will find your current PHP version. The Site Health screen also flags whether your PHP version is recommended, below recommended, or end of life, and provides a direct explanation of the risk.
Alternatively, check in your hosting control panel. cPanel shows your PHP version under Software > Select PHP Version. This is also where you change it. If your host uses Plesk, it is under Websites & Domains > PHP Settings. If you have server access, php -v in the terminal returns the CLI PHP version, note that the CLI version and the web server PHP version can differ on some hosts.
PHP version updates occasionally break plugin or theme compatibility. This is less common than it used to be, most well-maintained plugins have supported PHP 8.x for years, but it still happens with abandoned or poorly maintained plugins. Never update PHP on production without testing first.
The PHP Compatibility Checker plugin (by WP Engine) scans your installed plugins and themes and reports known compatibility issues for a specified PHP version. Run it on your production site before attempting any update to get a quick read on potential breakages. It is a useful first filter but not exhaustive, actual runtime testing on staging is the reliable check.
Clone your site to a staging environment, switch the staging site to the new PHP version in cPanel, and test it thoroughly. Test the homepage, category pages, single posts, the admin, and any dynamic functionality, WooCommerce checkout, membership login, booking flows. If everything works on staging, update production with confidence. If something breaks on staging, you have the time to investigate without any visitor impact.
The most frequent PHP 8.x compatibility problems fall into a few categories. Deprecated functions: functions that existed in PHP 7.x but were removed or changed in 8.x. The most common example is the removal of deprecated string manipulation functions and the each() function. Well-maintained plugins addressed these by 2021; plugins not updated since then may still contain them.
Stricter type handling: PHP 8.0 introduced more aggressive type checking and made previously silenced type errors into thrown exceptions. Code that passed a null where a string was expected, or compared arrays loosely, may now throw fatal errors where it previously produced incorrect but non-fatal results. This catches real bugs but can break plugins that relied on PHP's previously permissive coercion.
Named arguments: PHP 8.0 introduced named arguments. Plugins that use call_user_func_array() with positional arguments against functions that changed parameter order may break. Again, actively maintained plugins have dealt with this. Abandoned plugins have not.
If a plugin you depend on breaks on PHP 8.x and the last update was three or more years ago, treat that as a signal to find a maintained alternative rather than staying on an EOL PHP version indefinitely. The plugin ecosystem for WordPress is large enough that a maintained alternative almost always exists.
In cPanel, go to Software > Select PHP Version. This interface shows your current PHP version and a dropdown of all available versions. Select your target version and click Set as Current. Changes take effect immediately, no server restart required.
The same interface lets you configure PHP extensions (enable or disable individual modules like imagick, intl, redis) and PHP directives (memory limit, max upload size, max execution time, error reporting level) without editing php.ini directly. This is useful if you need to increase memory_limit for WooCommerce or upload_max_filesize for a media-heavy site.
If a PHP version update causes an unexpected problem on production, you can revert to the previous version in the same cPanel interface immediately. The rollback is instant. This is one reason why staging testing is recommended but not the end of the world if skipped for a minor version update, you can roll back within seconds if something goes wrong, then investigate on staging at your leisure.
Beyond the version number, several PHP ini settings affect how WordPress behaves. memory_limit is the most commonly encountered: WordPress requires a minimum of 64MB, recommends 256MB for complex sites, and WooCommerce often performs best with 512MB or higher. If you see "Allowed memory size exhausted" errors in WordPress or PHP error logs, increase this via cPanel's PHP settings.
max_execution_time controls how long a PHP script can run before timing out. The WordPress default is 30 seconds. Sites running large imports, complex WooCommerce order processing, or backup plugins may need 120–300 seconds. upload_max_filesize and post_max_size determine the maximum size of file uploads, if users cannot upload media above a certain size, these are the settings to check. All three are configurable in cPanel's PHP settings interface without server access.
Every HostBible hosting plan supports PHP 8.x with easy version switching in cPanel. Run your WordPress site on a supported, fast PHP version with no configuration headaches.
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