You know about WordPress updates. You probably know about plugin updates. There is a third one underneath both of them that almost nobody mentions, and it is the one your host quietly decides for you.
PHP is the programming language WordPress is written in. Your site runs on whatever version of PHP your server provides. And like everything else in software, PHP versions reach end of life and stop receiving security fixes.
How to check yours in thirty seconds
You do not need a developer for this.
Log into WordPress, go to Tools, then Site Health, then the Info tab. Open the Server section. Your PHP version is listed there.
WordPress will often tell you outright if it considers your version outdated, on the Status tab of the same screen. If you see a note about an outdated PHP version, that is not cosmetic advice.
The PHP project publishes a support timetable. Each release gets active support for roughly two years, then a year of security fixes only, then nothing. Once a version is past that, no more patches, whatever gets discovered afterwards.
Why it matters more than it sounds
Security. An unsupported PHP version means the layer beneath your entire site stops getting fixed. You can keep WordPress and every plugin perfectly current and still be sitting on unpatched foundations. It is the least visible risk on a WordPress site because nothing in your admin makes a fuss about it.
Speed. This one is unusually concrete. PHP 7 was a large performance jump over PHP 5, and PHP 8 improved again. Moving from a genuinely old version to a current one can meaningfully cut your server response time with no other changes at all. It is one of very few speed fixes that costs nothing and requires no design decisions.
Compatibility. Plugin authors set a minimum PHP version and raise it over time. Sooner or later a plugin you rely on requires a version newer than yours, and you are stuck: you cannot update the plugin, so you stop getting its security patches too. One outdated thing starts blocking another.
Why hosts leave you behind
Some hosts upgrade PHP for you automatically. Many do not, because upgrading a customer's PHP version can break their site, and a broken site means a support ticket. It is safer for them to leave you where you are and let you ask.
So the version you are on is often just the version that was current when your hosting account was created. If that was 2019, that is where you still are.
The control is usually in your hosting panel, under something like Select PHP Version, MultiPHP Manager, or a PHP settings tab. On managed hosts it may be a setting in their own dashboard. On a few, you have to ask support to change it.
Do not just flip the switch
Here is the part that catches people. Changing PHP version is a single dropdown, it applies instantly, and it can take a site down in a way that is not obvious how to undo if you do not know where you started.
What breaks is old code. A plugin abandoned in 2018 that calls a function PHP 8 removed. A theme with deprecated syntax. Custom code a developer wrote years ago in your functions file. When PHP hits something it no longer understands, you get a fatal error, and fatal errors take out the admin too.
The other trap is version jumping. Going from PHP 7.4 to 8.3 in one move is four major-ish steps at once. If it breaks, you have no idea which change did it.
The fix: move up one version at a time, check the site between each, and write down the version you started on so you can put it back instantly.
How to move up safely
- Update everything else first. Current WordPress core, current plugins, current theme. Most PHP compatibility problems are simply old code, so updating fixes them before you start.
- Delete what you do not use. An abandoned plugin you have not touched in three years is the most likely thing to break. Removing it is easier than fixing it.
- Take a full backup. Files and database, stored off the server.
- Test on a copy of the site, not the live one. This is the single most important step. Duplicate the site somewhere private, change PHP there, click through everything.
- Know the way back. Note your current version. If live goes wrong, switching the dropdown back is usually an instant fix, which is why writing it down matters.
- Change it at a quiet hour and then check the front end, the admin, your forms and your checkout in a private browsing window.
If something does break and the site will not load, most hosting panels let you change PHP version without needing WordPress to be working, since it is a server setting. That is your escape hatch.
Where this fits with Up Speed
PHP version is exactly the kind of maintenance that falls between the cracks. Your host considers it your decision. You do not know it exists. It sits there for four years getting slower and less patched, and nothing ever prompts you.
Testing a PHP change on a private copy of your site before it touches production is what a staging environment is for, and staging is included on the Professional plan, along with Wordfence firewall, iThemes hardening, two-factor login, Google PageSpeed work and 24 hour priority response. Speed and PageSpeed work sit on that tier too, which is where a PHP upgrade usually pays off most obviously.
Every Up Speed plan covers the groundwork that has to happen first: core, theme and plugin updates tested before they go live and rolled back if one breaks, scheduled off-site backups with 30 day retention, and a plain-English monthly report. Getting current is most of the battle, and it is the part that makes a version change survivable.
Not sure what you are running? A free site audit will tell you where your PHP version sits and what would need updating before you move.