PHP Versions Explained
How PHP Release Branches Work
A PHP version is a specific release of the language and its engine, identified by a major and minor number. Each branch follows a published life cycle that tells users how long it will receive fixes.
The life cycle has three main stages. During active support, a branch receives bug fixes as well as security fixes. It then moves to security-only support, which covers serious vulnerabilities. Finally it reaches end of life, when no further fixes are published. The official PHP website lists current dates, so check there for the status of a given branch.
Why Outdated Versions Are a Risk
Running an end-of-life PHP version exposes a website to known vulnerabilities that will not be patched. Attackers often scan for sites running old software, because published details of a flaw make exploitation easier. A site can be compromised even when its own code is well written.
Compatibility is the other concern. Newer PHP versions remove deprecated functions and tighten some rules. An application written for an old version may show errors or stop working after an upgrade, and extensions or themes may lag behind the newest release. Some settings also change between versions, which is relevant to php.ini configuration.
Upgrading Safely and Choosing a Version
Upgrades are safer when they are planned. The usual approach is to test the site on a copy running the new version, check the logs for deprecation notices, and update plugins, themes or libraries that depend on specific behaviour. A separate test environment makes this possible without risking the live site.
When choosing a version, look for one that still receives security updates and that your software supports. Many applications list the PHP versions they are tested with, and a host that offers several versions lets you match each site to its requirements. PHP's role on the web is covered in what PHP is.
Frequently asked questions
What happens if my PHP version is end of life?
The PHP engine keeps running, but it no longer receives security fixes. A site may continue to work for a time, yet every newly discovered flaw in that version stays open. Moving to a supported version is the standard way to close that gap, after testing compatibility.
Can I run several PHP versions on one hosting account?
It depends on the host. Many providers allow different sites or directories to use different PHP versions, which is useful when one application needs an older release. Whether this is available in your plan is usually shown in the hosting control panel or the provider's documentation.