I saw a message suggesting I should “update PHP”. What does that mean?

When you use a script on your website (such as WordPress), that script runs a software program called PHP on our servers. The PHP software interprets the programming code in the script and generates the web pages people see.

Like any other software, PHP comes in different versions. Scripts are written to work best with certain versions of PHP.

We let customers choose between different versions of PHP, but you should choose a recent version that’s compatible with your scripts.

On this page:

I know nothing about this. What should I do?

If you’re not sure what version of PHP to choose, do this:

  1. Update your scripts (including applying all WordPress plugin and theme updates) on a regular basis, so you’re never using outdated versions; and
  2. Choose the version of PHP marked “recommended for most customers” in our “My Account” control panel.

This combination almost always offers the best combination of security, performance, and compatibility.

After doing this, check your website and make sure it still works as it did before. if it does (it usually will), you’re finished. If it doesn’t, set the PHP version back to what it was before to make the site work properly again, and contact us for assistance.

Is there a way I can check my WordPress site for compatibility before switching to a new PHP version?

If you want to be extra cautious, you can install a handy plugin called PHP Compatibility Checker on your site before you switch to a newer PHP version. It will try to flag any potential problems.

Why do I need to update PHP?

An analogy will help explain this:

  • Scripts such as WordPress are like programs on your computer
  • PHP is like the Windows or Mac operating system on your computer

Think about what happens when you install or upgrade a program like Microsoft Word on your computer. The program is written to be compatible with certain operating systems. For example, Microsoft Word 2007 was written to be compatible with Windows XP, but Microsoft Word 2016 requires at least Windows 7.

When you install new software on your computer, you need to use a reasonably modern operating system, too. You probably don’t worry about every last detail of what versions you’re using, but you might have problems if the operating system on your computer hasn’t been updated for years. For example, if you try installing Microsoft Word 2016 on the decade-old Windows XP operating system, it might not work.

The same is true with scripts like WordPress, and with PHP. As you upgrade your scripts (“programs”) over time, you should also make sure you’re using a fairly recent version of PHP, the “operating system” those scripts run on.

People who create scripts usually write them to work with several different versions of PHP. But they expect you to be using something fairly recent, not a PHP version that’s many years old.

Fortunately, updating PHP is much easier than updating your computer operating system — you just click the button in our control panel. (And unlike computer upgrades, you can instantly click back to an older version of PHP if you have trouble.)

Are there any technical guides about the differences between versions?

The PHP authors provide guides explaining the differences between versions.

Why can’t I just use an old version of PHP forever?

The reason this won’t work is the same reason you can’t just use an old computer operating system (like Windows XP) forever. You’ll encounter more and more situations where things just don’t work properly.

Newer versions of PHP are generally more secure, have fewer bugs, and run your scripts more quickly. Of course, that’s really just another way of saying that by modern standards, older versions of PHP are insecure, buggy, and slow.

People who write scripts (including scripts like WordPress plugins and themes) generally don’t use old PHP versions and don’t test their scripts to work on those old versions. They really want you to update PHP.

If you keep using a very old version of PHP, your site will eventually stop working when you install a script update (like a WordPress plugin update) that’s incompatible with the old PHP version.

Why doesn’t Tiger Technologies update PHP for me?

We want all our customers to keep their scripts updated and use recent versions of PHP. But because we don’t actually know if you’re updating your scripts to be compatible with recent PHP versions, we can’t force you to update PHP as often as we think you should update it.

For example, if you hired someone to write a custom script for you ten years ago, and you’ve never updated that script, it’s possible that switching to a newer version of PHP might cause it to stop working. (This is similar to updating your computer operating system, where old programs can fail if you haven’t updated them for a few years.)

Because of that, we let people use older versions of PHP much longer than we think think they should use them — but we strongly encourage you to update both your scripts and PHP on a regular basis.

Eventually, the PHP version on your site might get “upgraded” as a side-effect of us removing a very old ancient PHP version entirely, but that would only happen years after we begin nagging you to do it yourself. If that happens, you won’t have a chance to temporarily switch back to an older version of PHP if things don’t work properly. It’s far better to do it yourself, at a time when it’s convenient for you to test things afterwards.

(Also, if we did upgrade PHP for you automatically, things wouldn’t be very different. We’d still need to send you a notice similar to the one we send now, except it would say “we upgraded PHP for you and you should check your site” instead of “please upgrade PHP at a time convenient for you and check your site”. But that might mean your site has trouble for some time until you read the notice, especially if you’re on vacation.)

What if I update PHP and then have problems?

You probably won’t notice any change after upgrading PHP, except that your site may run a little faster. Problems are rare if you’re using scripts that have been updated recently.

Still, after you choose a newer version of PHP in our control panel, you should test your site thoroughly. If you do see any problems, just switch it back to the original older PHP version in our control panel. Your site will again work immediately, and you can let us know the details of the trouble you had. We’ll be glad to help.

That said, almost everyone who contacts us about this simply hasn’t first updated the scripts they use, such as all their WordPress plugins and themes. Be sure to do that before you update PHP.