Updating your PHP Version

Moving to a higher PHP version after an upgrade

Before you begin your upgrade, you may wish to check which PHP versions are available.

After you go live with an upgrade, you will likely want to update your PHP Version. For example, if you were running Zen Cart 1.5.1, you were probably using PHP 5.6 or 7.1. After deploying Zen Cart 1.5.7, you will want to update your PHP version to PHP 7.4. And after deploying Zen Cart 1.5.8, you will want to update your PHP version to 8.0 or 8.1.

In extreme cases, such as upgrades from much older versions (1.5.1 to 1.5.8a, for example), you may have to change the PHP version prior to even running zc_install. But if your site only one version behind, typically the new version will work with the highest version (or even second highest version) of PHP supported by the old version. For example, Zen Cart 2.0.0 works with PHP 8.1, which is one of the higher versions recommended for Zen Cart 1.5.8, the prior release.

You will want to run the latest PHP version which is appropriate for your Zen Cart version. See Server Requirements for running Zen Cart.

The process of changing your PHP is server-specific, depending on whether your hoster uses PHP Selector, MultiPHP Manager or some other utility. See PHP Configuration for more information.

Your hoster likely provides a knowledge base with instructions. Contact your hoster if you are unsure how to proceed.

Note: In some environments, changing your PHP version can reset your memory_limit setting. Be sure to go to the version page after updating PHP to verify the setting of your PHP Memory Limit. For more details, see memory_limit.

Watch out for new PHP warnings after updating PHP

Understanding problems that occur after upgrading PHP versions explains why PHP warnings can suddenly start occurring.
An explanation of how to fix them is provided in PHP Warnings and Deprecated messages after upgrading.
If you are suddenly seeing “out of memory” PHP notices, your memory_limit setting has likely been reset. Go to the version page to verify the setting of your PHP Memory Limit, and update it if required - see PHP memory_limit.

Still have questions? Use the Search box in the upper right, or try the full list of FAQs. If you can't find it there, head over to the Zen Cart support forum and ask there in the appropriate subforum. In your post, please include your Zen Cart and PHP versions, and a link to your site.

Is there an error or omission on this page? Please post to General Questions on the support forum. Or, if you'd like to open a pull request, just review the guidelines and get started. You can even PR right here.

Last modified January 21, 2024 by Scott C Wilson (44968a8b).