Upgrading your WordPress site to the latest PHP version

Overview

PHP 7 offers several improvements over earlier versions. You can read more about those here:

A major issue with PHP 5.6 is that it consumes more memory than necessary and runs slower than newer versions. If your WordPress site is running on PHP 5.6, it's running slower than it would on PHP 7.

The latest WordPress core software releases have been compatible with PHP 7 for a few years now. Upgrading to PHP 7 is a quick and easy way to get more performance for your WP site and server.

Potential software conflicts

If you haven’t been diligent about maintaining your WP software, plugins and theme versions and making sure they’re well supported by their developers, you may have code that’s incompatible with PHP 7.

If you encounter issues, you can easily downgrade back to PHP 5.6 so your site remains functional while you investigate further.

If you run into any problems, DreamHost Support is happy to assist.

How do I know if I need to upgrade?

DreamPress hosting plans

  1. Navigate to the DreamPress page.
  2. To the right of your domain, click the Manage button.
  3. At the top under your domain name, you should see the PHP version:
    • If you see PHP 7.1, 7.2, or PHP-FPM, you are already on a supported version of PHP 7.
    • If you see PHP 5.6 or PHP 7.0 or if you specifically requested a downgrade to PHP 5.6 on PHP-FPM, you should upgrade to PHP 7.1 or 7.2.

All other hosting plans

This includes any WordPress site installed on a plan other than DreamPress. For example, Shared Hosting, VPS, or Dedicated.

  1. Navigate to the Manage Domains page.
  2. Click the 'Edit' link to the right of a domain.
  3. On the domain's settings page, look under the 'Web Options' section for the PHP version:
    • If it says PHP 5.6 or 7.0, you should upgrade to PHP 7.1 or 7.2.

Which version should I upgrade to?

It's highly recommended that you upgrade to the latest PHP version if your site's software is able to do so without issue. The latest version in the panel for 2018 is PHP 7.2. New PHP versions are typically available at the end of every calendar year. PHP 7.3 was released in December 2018.

The latest version is the one that will be supported the longest and has the most fixes to improve performance. Several studies show that PHP 7.2 offers a 20–30% speed improvement over PHP 7.0 and a 250-300% speed improvement over PHP 5.6.

If you encounter an issue with the latest version, you can try the next most recent version without much difference in performance or support.

It is NOT recommended that you choose PHP 7.0 as this version reached its end of life (no longer updated or supported) in December 2018.

Each PHP version offers two options: FastCGI and CGI. Typically you should choose FastCGI as this offers faster performance for most sites. If your site’s PHP version is currently set to CGI, you may have at one point encountered performance issues with FastCGI which prompted the change to CGI. You are welcome to try either one to compare performance.

Preparing your WordPress site for a PHP 7 upgrade

Using the checklist below will help minimize the risk of issues when upgrading the PHP version, however, there is always a small chance of an error or issue after an upgrade due to the thousands of themes, plugins, and customizations available to WordPress.

Remember that you can always try the upgrade and downgrade if there’s an issue. These steps aren’t required, but they are highly recommended for a PHP upgrade as well as for the regular maintenance and security of your site.

Checklist

  • Are you on the latest version of the WordPress core software?
  • Do you have any pending updates displaying in your WordPress Admin dashboard?
  • Do you have any older themes or plugins that haven’t been updated by the developer in over a year, or any paid themes/plugins that have expired licensing for updates?
  • Do you have any customizations written in PHP that you need a developer to review?

Tools to help make this research easier

  • Install the 'xGEN Plugin Date Information' plugin. This plugin displays the date the plugin was last updated on the plugins page in the dashboard. If you have applied all available updates to your plugins, this date can help you identify plugins that have not received an update from its developer in over a year.
  • Set your One-Click Install to upgrade WordPress core files automatically in the panel.

Testing the upgrade using a staging site

A safe way to test the new PHP version is to create a staging website. This staging site will become a duplicate of your existing live website. You can then proceed to run tests on this staging site to see how it reacts. If nothing unusual happens, you can then proceed with upgrading your live website. View the following articles for information on how to create a staging website for WordPress:

Upgrading to PHP 7

DreamPress sites

DreamHost support can upgrade your site's PHP version for you. To request this, submit a support ticket in your panel. Make sure to include your DreamPress site name and the version you'd like to be upgraded to.

WordPress sites on all other hosting plans

The following guide explains how to change the PHP version of your site:

See also

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Article last updated PST.