Why your PHP version matters for speed and security

If your website runs on WordPress, WooCommerce, Joomla, Magento, Laravel or a custom PHP application, there is a setting on your server that quietly affects how fast pages load and how exposed you are to attackers. It is the PHP version. Many small-business sites are still running a release that stopped receiving security fixes years ago, simply because nobody checked. This article explains why that matters and shows you how to find out what your site is using.

What PHP does for your website

PHP is the programming language that runs on the server and builds your pages. When a visitor opens your home page, PHP reads your theme and plugins, fetches content from the database and sends back finished HTML. The visitor never sees PHP directly, but every dynamic page depends on it.

The version of PHP installed decides which language features are available, how efficiently code runs, and whether known security holes have been patched.

How the PHP support lifecycle works

The PHP project releases a new minor version roughly once a year, such as 8.1, 8.2 and so on. Each version then goes through two phases:

• Active support: bugs and security issues are fixed, and regular point releases are published.
• Security fixes only: only critical security problems are patched, for a further limited period.

After that, the version reaches end of life. No more fixes of any kind are released by the PHP project. The whole PHP 5 and PHP 7 families are long past that point, and so are the earliest PHP 8 releases.

Rather than relying on dates quoted in blog posts, which go stale, check the official Supported Versions page on php.net. It shows a simple chart of which branches are in active support, which receive security fixes only, and which are end of life. Bookmark it and look once or twice a year.

The security risk of an end-of-life PHP version

Once a branch is unsupported, any newly discovered vulnerability in PHP itself stays open forever on servers still running it. Attackers know this and scan for old versions.

There is a second, less obvious risk. Plugin and theme developers stop testing against old PHP releases, and security updates for those plugins may require a newer version. A site stuck on old PHP often ends up stuck on old plugins too, and outdated plugins are among the most common entry points for website hacks.

A note about hosts that backport fixes

Some Linux distributions and managed hosts patch security issues into older PHP packages themselves. That can reduce the risk, but it depends entirely on your provider, and it does not help with plugin compatibility. Ask your host directly rather than assuming.

Speed gains in newer PHP releases

PHP 7 brought a major rewrite of the engine that made typical applications run far faster and use less memory than PHP 5.6. The PHP 8 series continued that work and added a JIT compiler, plus steady optimisations in each minor release.

For a business website, faster PHP means:

• Lower time to first byte on pages that cannot be served from cache, such as carts and checkout
• More requests handled within the same CPU allowance on shared hosting
• Admin screens and reports that feel less sluggish

How much improvement you see depends on your code, database and caching. The gains are real, but they will not rescue a site weighed down by huge images or a slow database. Run PageSpeed Insights before and after to measure the difference on your own pages.

How to check which PHP version your site uses

There are several quick ways. Use whichever matches your access.

From your hosting control panel

In cPanel, look for Select PHP Version or MultiPHP Manager. Both show the version assigned to each domain. Plesk shows it under the domain’s PHP Settings, and most other panels have a similar page.

From the WordPress dashboard

Go to Tools, then Site Health, open the Info tab and expand the Server section. The PHP version is listed there. Site Health will also warn you on its Status tab if your version is considered outdated.

Using a temporary phpinfo file

1. Create a file named something unguessable, like check-7f3a.php, containing a call to phpinfo().
2. Upload it to your site’s root folder and open it in a browser.
3. Read the version at the top of the page.
4. Delete the file straight away, because it reveals server details that attackers find useful.

From the command line

On a VPS, run php -v over SSH. Be aware that the command-line PHP can differ from the version serving web pages, especially when a panel runs several versions side by side.

Signs your PHP version is holding the site back

• Plugin or theme update notices saying a higher PHP version is required
• A Site Health or control panel warning about an outdated version
• Deprecated function warnings appearing in error logs
• A developer telling you a new feature “needs a newer PHP”
• Slow admin pages despite reasonable hosting resources

What to do after you know your version

Write the version number down, then compare it with the php.net Supported Versions chart. If your branch is still supported, simply keep an eye on it. If it is in security-fix-only mode, plan an update within the coming months. If it is end of life, treat the change as a priority, but do it carefully: switching directly on a live site can break older plugins or custom code.

Test the change on a staging copy first. If you would rather not handle this yourself, our support team can check compatibility and move you safely, and all our Linux hosting plans let you choose from multiple PHP versions.

Frequently asked questions

Can changing the PHP version break my website?

Yes, it can. Older themes, plugins or custom code may use functions that were removed in newer releases. That is why it is safest to test on a staging copy and keep a backup before switching the live site.

Is PHP 7.4 still safe to use?

The PHP 7 series no longer receives official security fixes from the PHP project. Unless your host provides its own backported patches, a site on PHP 7.4 should be planned for an upgrade.

Does the PHP version affect SEO?

Not directly. Search engines do not read your PHP version. Indirectly, faster server responses help page experience, and a hacked site with injected spam can seriously damage rankings.

Why does my host still offer old PHP versions?

Hosts keep older versions available so that legacy sites do not break overnight. Availability in the menu does not mean a version is still supported or recommended.