Which PHP version should you choose?

Which PHP version should you use? Choose the newest PHP version that your CMS, your theme and all your plugins support, and stay away from versions that no longer receive security updates. In practice that is usually the latest version or the one before it. The PHP version is the most underestimated cause of a broken website, and it cuts both ways: too old is insecure and slow, too new breaks code that is no longer maintained.

How long is a PHP version supported?

Every year, around the end of November, a new PHP version is released. Each version gets two years of active support, with bug fixes and security fixes, followed by two more years of security fixes only. In September 2026 that looks like this:

• PHP 8.5 and 8.4 — active support.
• PHP 8.3 — security fixes only, until the end of 2027.
• PHP 8.2 — security fixes only, until the end of 2026.
• PHP 8.1 and older, so 7.4 and 8.0 as well — no fixes at all any more. A vulnerability discovered today stays open.

The current dates are on php.net, on the page with the supported versions.

Too old or too new

Too old: no security updates, noticeably slower, and recent plugins refuse to install or update on it. Too new: an old theme or a plugin that is no longer maintained uses functions that have disappeared from PHP. The result is a white page, a 500 error or the message that there has been a critical error. So only choose the very latest version once your CMS and your most important plugins explicitly support it.

Checking whether your site is ready

1. See which version you are running now. In WordPress it is under Tools → Site Health, on the Info tab under Server.
2. Look up what your CMS supports. WordPress, Joomla, Drupal and PrestaShop publish, per release, which PHP versions they work with. Never go higher than what is stated there.
3. Update everything first: the CMS, the theme and every plugin. Update first and only then switch: what breaks is an old plugin on a new PHP version.
4. Go through your plugins. A plugin that has not had an update for two years is the first candidate to break. Find a replacement before you switch.
5. Think about what runs next to the CMS: a custom script, a link with your accounting software, an old form. Nobody updates that automatically.
6. If you have a test copy of the site, switch that one first and test there.

Switching the version

With our hosting you choose the PHP version yourself in the control panel, and you do so per site. The switch is undone just as quickly. The steps are in changing the PHP version of your website.

Pick your moment. Not on a Friday evening and not during a promotion in your webshop, but when you have time to test and to switch back. Afterwards, check more than just the home page:

• the contact form, right up to the email that has to arrive
• the ordering process, right up to the payment step
• logging in and the admin area
• scheduled tasks, such as a nightly import or export

Errors after the switch

1. Switch back to the previous version. Your site works again and you can look for the cause calmly.
2. Read the error message. The error log, or the email WordPress sends to the administrator after a critical error, contains a file path. The folder name in that path is the plugin or theme that causes the error.
3. Update that plugin, replace it or deactivate it, and try the switch again.

The messages you see most often:

• Call to undefined function — the code calls a function that no longer exists in the new PHP version, or that comes from a PHP extension that is not loaded for this version.
• Deprecated — not an error but a warning: this still works, but will disappear in a later version. The site keeps running. If such messages appear on the page, turn off the display of errors.
• A white page without any text — a fatal error whose display is turned off. The message is in the error log.
• Allowed memory size exhausted — not a version problem, but the memory limit. See raising the PHP memory limit.

Do not leave a site on an outdated version for good because a single plugin would otherwise break. That is postponement: the vulnerability in the old PHP version remains. What the error codes themselves mean is explained in error codes 403, 404 and 500.

Frequently asked questions

Will a newer PHP version make my site faster?

Usually, yes. The move from a 7 version to an 8 version is generally noticeable; between two consecutive 8 versions the difference is small. Switch for the security; the speed is a bonus.

Does WordPress work on the latest PHP version?

WordPress core follows quickly, but often labels its support for a newly released PHP version as beta at first. The weak link is themes and plugins.

My site runs fine on an old version. Why should I switch?

Because "it works" says nothing about security. A version without security fixes becomes more vulnerable every month, and one day an update of your CMS will refuse to install. Then you switch under time pressure.

Still stuck?

Send us your domain name and the error message you got after the switch via contact. There is a safety net too: we back up our hosting plans every day and keep each backup for 14 days, and you request a restore through support. More about that on backup and restore.