PHP 7 is twice as fast as PHP 5.x and requires one fraction of the server memory.

Does activating PHP 7 from version 5.6 make a difference in speed test scores? There is no measurable load-time difference in milliseconds. None. Why no improvement?

Some claim to add PHP 7 instead of a version 5.6 speeds up page loads by 300 milliseconds on a cache-less site. We don’t see that improvement evaluating with normal online tests like Pingdom.com or WebPagetest.org.

On a well-optimized site, there is no speed change evident. But the same can be said about caching plugins, minification plugins, and CDNs. With proper origin optimization, there’s little benefit from inadequate speed fix-it attempts. Band-aids.

Our PagePipe blog is a well-optimized site. So why would we even want to risk a change? We write about plugin technology and speed. We stay current to “walk the talk.” We also have an insatiable curiosity. So we did it.

A 3,760-word article at WP Elevation is about the pain of producing websites. The article expresses everything we hate about website creation. The thought of building “explosive live hand grenades” stresses us. Just reading the article was stressful. Why?

Because it’s true. The nit-picky horrors described are exactly what occurs during web projects. Client or website owner expectations are high. Their technical knowledge is often low.

A new monster arose on the WordPress horizon.

The fragile nature of WordPress and PHP v7.x.

Why does adding PHP 7.x break your site? Our choice to transition our GoDaddy-host-server to PHP 7 rattled our nerves. And we’re initiated in this stuff. Our experience is a good example of what goes wrong. Upgrading PHP version 5.6 to version 7.x is a simple C-panel setting – but not without potential consequences.

PHP 7 released long ago on December, 3rd, 2015. GoDaddy didn’t add this server option for a year and a half. Why? Because they knew the changes might break hundreds of thousands of WordPress websites. They left it up to users to perform the update. And they delayed the service call costs for as long as possible. The GoDaddy default version was set to 5.4. Making users choose their poison was smart. Users then are responsible for breakage. Or dialing back the PHP version themselves – or tracking down fixes. GoDaddy is blameless – sort of.

Above: Pie chart – Percentages of WordPress sites using different PHP versions.

Risk breaking my site? Why even care about PHP version 7.x?

PHP is the code of WordPress, a server-side programming language. It first appeared in 1995. All themes and plugins use PHP, too. Upgrading your site to run on PHP 7 instead of PHP 5.6, you’ll improve the performance of WordPress core by 2x. That’s right. Twice as fast is the typical gain in core speed. We anxiously waited and watched for this no-extra-cost, speed opportunity. Free speed. Most vendors upgraded long ago. So we felt snubbed. But we didn’t change hosts. We like bragging about good speed achieved under the worst conditions!

So how faster does WordPress core load? We should see a 100- to 300-millisecond improvement. But we never see betterment in testing. Updating PHP is a theoretical improvement – not an actual improvement.

PHP running twice as fast doesn’t mean your website loads twice as fast. We’ve never seen significant, measurable differences switching back and forth between PHP 5.6 and PHP 7.3 on various hosts. For us, it’s a theoretical improvement in speed. We think it’s good – but if you don’t change versions – no problem for us. It might be a problem for you at a future date.

PHP 7.x isn’t going to break WordPress – it may cause some of your plugins to malfunction. Perhaps your theme. But the result is the same, your site appears broken. You can test all your plugins using a free plugin. Naturally! We tested with:

★★★★★
PHP Compatibility Checker
Active installs: 30,000+
Compressed download: 1M

With this plugin above, you can check your site for PHP 7 compatibility.

★★★★★
Display PHP Version
Active installs: 40,000+
Compressed download: 11k

Display PHP Version plugin displays the current PHP version in the “At a Glance” admin dashboard widget. We like it.

So what broke after the change from 5.6 to 7.x?

1. Broken Link Checker – compatible – warning 1 – This plugin broke the site when viewed on an Apple iPad. Meaningless code was all over the screen. We disabled the plugin. This is plugin causing site drag anyway. Only use it during maintenance. Leave it disabled. On some host, they ban Broken Link Checker. Why? Because it overloads the server slowing down other sharing domains.
2. Simple Content Adder – We got a red flag for the file revisions.php. But we couldn’t find it breaking anything. We left it as-is.
3. SS Downloads – red flag – This favorite old plugin broke the site with PHP error screen. The plugin failed because it triggered a fatal error. The plugin is for email capture before PDF downloads. We had to dump the plugin. Presently, all our free downloads use MailChimp signup. We do product downloads with Easy Digital Downloads plugin on our store site.
4. Title Experiments Free – compatible but 7 warnings. We wrote plugin author, Jason Funk, and he updated the plugin to version 8.9 for PHP 7.1 compatibility. No more warnings. Thanks, Jason. [Jason later removed this plugin from the directory.] It caused global loading – site drag.
5. WordPress Popular Posts – compatible – 24 warnings. The plugin stopped gathering data for page visits. This is the primary reason we use this plugin. It’s very popular with 300,000+ active installs (v3.3.4) The new version 4.0.0 is now PHP 7.x compatible. It has slow Font Awesome onboard but it’s not enqueued. We’re thankful. We like the new GUI control panel for the plugin. The original plugin was a 125k zip file. The new one is 759k. Most extra weight is font overhead for the control panel. It doesn’t affect your site’s front end. This newest version is now available on the WordPress directory. We don’t use this plugin any more because of site drag.

How fast was PagePipe home page after the switch to PHP 7.x?
699 milliseconds unprimed cache and 440 primed. Superfast even on GoDaddy mechanical, shared server with no CDN.

So a quick comparison of primed cache:
PHP 7.2: Pingdom NY PagePipe home page – primed cache: 559ms.
PHP 5.6: Pingdom NY PagePipe home page – primed cache: 567ms.

8 milliseconds gain with TTFB fluctuations. Maybe? Insignificant gain on an optimized page. We’d be better off economizing in other areas.

Why no big gains? Because we have super optimized the homepage. There’s a point of diminishing returns. Only fat bloated slow websites benefit from the PHP version switch.

PHP gains are overrated and exaggerated. A bloated site gets the most improvement. So PHP is a cheap test of site bloat. Big speed improvements from PHP indicates a big potential from the investment in site origin optimization.

“None of my speed tests provided clear evidence that my site now loads faster on PHP 7 compared to PHP 5.6.” – OFFSITE REFERENCE: https://wpsmackdown.com/switching-to-php-7/