PHP is evolving, and you must keep pace with updates to maintain a secure WordPress site.
You also need to know how to roll an update back in case there is a PHP compatibility problem.
Discover how to avoid update headaches, and what else needs to be checked when you change PHP versions.
What is PHP?
PHP is the coding language that WordPress, plugins, and themes use.
Like all coding and software, it gets improved over time and support is eventually dropped for older versions.
Why We Have to Update Our PHP Version
Here’s a scary set of stats.
Most WordPress site owners are still on some version of PHP 5.x.
Support for anything below 5.6 has already been dropped.
And support for 5.6 will be dropped Dec 31, 2018.
PHP 7.0 has been out since Dec 2015.
Active support for it stopped in 2017 and security support will end Dec 3, 2018.
Lack of PHP version support means that anyone using an older version will have a gaping security hole on their site if they don’t update.
Support for both 7.1 and 7.2 is still active even though 7.3 has recently been released.
You can see dates for all PHP version support here.
You need to update to one of these newer PHP versions by Dec 31, 2018.
Check and Change Your PHP Version
If you’re still on PHP 5.x then you may want to check your site for PHP 7.x compatibility first.
The jump from 5.x to 7.x is huge. The jump from one 7.x to another 7.x is not as big, so the compatibility checker won’t help much with that.
READ: How and Why to Switch to PHP 7 for more on this change and links to the compatibility tester.
Update PHP at Your Host
The PHP code is supplied by your host because they use it for running certain things on your server. And, they make it available for WordPress, plugins, and themes to use.
So, you have to update your PHP version from within your hosting account.
The easiest way to do that is via cPanel.
See this video tutorial for how to check and change your PHP version on A2 Hosting and SiteGround.
See this video tutorial on how to fix issues you may run into with PHP 7.2
The PHP Change Will Be Messy
We stayed at PHP 5.x for years, so long in fact, that most site owners have never had to concern themselves with updating their PHP level.
Well, those days have been over since 2016 when we were encouraged to make the leap to PHP 7.0.
(Don’t ask why we skipped 6.0 it’s a long story.)
Most plugins have continued to remain backward compatible to 5.6.
But that is also coming to an end.
WordPress 5.0 is only being tested on PHP 7.3. There is no guarantee that it will be backwards compatible with older PHP version.
And, there’s no guarantee that your current set of plugins will work with PHP 7.3.
In fact, as of Nov 2018, some hosts aren’t even offering PHP 7.3 because it is so new.
See the problem?!?
The Plugins are the Real Issue
As more plugin developers prepare for WordPress 5.0, they are going to have to make tough decisions.
They may need to completely rebuild their plugins to be both Gutenberg and PHP 7.3 compliant.
That may be too much and they may decide to throw in the towel.
In fact, a few premium (paid) plugins have already announced they will call it quits when WP 5.0 comes out.
Other plugin developers may choose to only test their plugin with the latest version of PHP and not bother to try to make it compatible with any lower version.
And there’s the rub.
All through 2019 we will have plugins in various states of PHP compatibility.
So, if you are currently at PHP 7.1, you may need to update to 7.3 to make a plugin work.
And that may break a plugin that is not yet 7.3 compatible.
See the problem?
How Will I Know What PHP Version My Plugins Need?
Good question.
To date, there is no listing for the minimum or tested PHP version required on the information graph of each plugin in the WordPress Plugins Repository.
So, the only true way you have to test is live on your site.
That’s not good.
In fact, you could do a plugin update and your site go whack!
That error or conflict could show up as:
- a new error warning
- lack of a function
- or even a white screen of death
Oh crap!!!
See this video tutorial on how to restore a plugin to a previous version with WP Rollback.
It will save your bacon if a plugin update goes whack due to a PHP version issue.
Not a Set and Forget Thing
It took several years for hosts, WordPress, and plugins to push for site owners to move from PHP 5.6 to 7.0 as the standard. (The release dates were only a year apart, but 7.0 was not the standard for at least 2 years more.)
In just 2 years, we’re already at 7.3. That’s super fast development!!
And, until WordPress does a better job of strongly encouraging plugin developers to get on the ball with PHP standards, we’re going to have a mess of mixed plugin compatibility.
It’s not like you’ll be able to set your PHP level and not have issues or have to touch it again for years either.
Which PHP Version Do I Want to Use?
Good question.
And the answer is – it depends.
All sites are different with various themes and plugins in use.
So, what works for one site owner may not work for another.
My advice – try the highest level available at your host and see what happens.
Report Compatibility Issues
BlogAid informs a village of users.
If you encounter plugin PHP compatibility issues, let us know in the comments.
Help us help each other.
Site Audit Plus Clients Get Extra Help
I keep my Site Audit Plus clients super informed about major site changes via
- our private Facebook group
- free member site
- and live sessions
I know their sites are clean and current, and that they have received the base education which empowers them to DIY their sites through all of this.
We discuss which levels of PHP work best, and report issues to help the whole village get through these big site changes calmly.
If you’ve been struggling to make sense of your site tech, and all the site tech changes, consider getting an audit and the amazing education that comes with it. Not to mention all the free, extra support, and the comradery of an educated group of site owners just like you.
This book could save you hundreds of dollars and months of frustration. Get it free with your subscription to
I did not encounter plugin difficulties but when I went from PHP 7 to PHP 7.2, I could no longer sign in to WordPress. I did not write down the error (sorry) but it was something to the effect that my version of WP was missing some file.
I then switched to PHP 7.1 and all was well. I have checked my site everything seems to be working (so far).
FYI I am on A2 Hosting using their Turbo (shared) hosting product. Hope this helps someone in the same situation. Best advice? Don’t panic if things do not go as planned. Switching back is easy peasy.
Thanks so much for letting us know, Gaye. Perhaps after the 5.0 update that file will be reinstated or work again. Be sure to jot down the whole error message so we can investigate further.