October 2026  ·  

2.5 min read

Your Speed Plugin Might Be Breaking Your Mobile Site. Ours Was.

We recently spent an evening fixing our own website and found four plugin settings quietly working against each other. Every one of them did exactly what its label promised. Together, they broke the site on phones.

This one’s a little embarrassing to write, which is exactly why it’s worth writing. We look after WordPress sites for a living. We check other people’s settings every month. And on our own site, the pricing section had been squeezed, on a phone, into four columns about as wide as your thumb.

Nobody had told us, and nobody would have. A visitor who runs into a broken layout doesn’t send an email about it. They just leave.

On a phone, before
77px
Width of each pricing card
$2,00
What $2,000 looked like
None
Pages with a canonical tag
On a phone, after
Full width
Each card stacks cleanly
$2,000
Every digit present
Every page
Canonical tag back in place

How we found it

By accident. We’d changed one small typography setting and wanted to see it on a tablet and a phone before calling it done. The typography was fine. The layout underneath it wasn’t: columns that should stack on a small screen were sitting side by side, shrunk to fit.

So we went looking for the cause, and along the way turned up three more settings doing things nobody would have guessed from reading them.

Every one of these settings did exactly what its label said. That was the problem.

Four settings, all doing their jobs

Each of these is a legitimate feature, switched on for a good reason. Here’s what each one promised, and what it actually did once it was sharing a site with the others.

Setting 01

Defer stylesheets

A real speed technique: let the page start drawing before every bit of styling has arrived. Our theme's version moved the main stylesheet to the bottom of the page, while the rules for phones and tablets kept loading at the top. When two sets of instructions are equally specific, the browser follows whichever it read last, so the desktop layout won on every screen size.
FixSwitch it off, clear the cache, and check the site on a phone the same day.
Setting 02

Critical CSS

Switching the first setting off fixed every page except the home page. That page had a second speed feature turned on, which saves a small bundle of styling for the top of the page and holds the rest back. Same idea, same side effect, one page only.
FixDelete the saved entry for that page, and don't regenerate it without checking mobile.
Setting 03

The page cache

Then the repaired home page still looked broken, because the caching plugin was handing out a saved copy of the broken one. Caching is one of the best things you can do for speed. It's also why so many owners make a change, see nothing different, and decide the change didn't work.
FixClear the cache after every change, then check again in a private browser window.
Setting 04

Hide redundant canonical link tags

Nothing to do with phones, but it turned up the same day. A canonical tag tells Google which address is the real one for a page, which matters because the same page gets reached with newsletter tracking codes, Facebook click IDs and so on. Our SEO plugin had a setting that removed those tags, with a note saying this helps avoid duplicate content. That's backwards: the tag is what protects you from it.
FixTurn the setting off and confirm a canonical tag appears on every page.

And one bonus for the collection: our button settings were loading a typeface that no button on the site actually used. Harmless, just dead weight on every page, and a good example of how settings quietly pile up over the years.

77px
Width of each pricing card on a phone
4
Settings, each doing exactly what it said
100%
Pages that were missing a canonical tag

Why this keeps happening

None of these are bad plugins, and none of these settings are wrong on their own. Each plugin is built and tested by itself. Your site isn’t one plugin. It’s a theme, a page builder, a caching tool, an SEO tool, maybe a CDN, and whatever else has been added over the years, all making decisions about the same page. The settings screens can’t warn you how those decisions interact, because each one only knows about itself.

The blind spot
Why nobody notices
Almost everyone checks their website on the computer they manage it from. The desktop version can look perfect while the phone version, which is how a big share of your visitors see you, has been broken for months. A settings screen tells you what a plugin intends. Only the page itself tells you what it did.

A ten minute check you can do yourself

You don’t need to understand any of the above to catch it. You need your phone and about ten minutes.

Check three pages on your actual phone. Your home page, your services or pricing page, and one blog post. Anything squeezed side by side, cut off, or scrolling sideways is worth a closer look.
Turn the phone sideways. Tablet widths break in their own ways.
Clear the cache before judging a change. Then look again in a private browser window, so you see what a stranger sees.
Test speed features the day you switch them on. Not whenever you next happen to visit your own site.
Find yourself the way customers do. Search Google for your business name and tap through. That version is the one your customers get.

If something looks off and you can’t tell which setting is responsible, that’s normal. These problems don’t announce which plugin caused them. Tracking down the one setting that’s doing it is the actual work.

What a retainer actually is
Mostly not heroic rescues
Mostly it's someone looking at the real pages on real screens every month, and noticing when two perfectly good settings have started arguing. Every This Gals Design Studio retainer includes that, whichever plan you're on.
See the retainer plans →
M
Michelle
Founder, This Gals Design Studio
WordPress developer, SEO strategist, and paid media manager with 13+ years of hands-on client work. HubSpot certified. Runs a deliberately small roster of retainer clients because that's where the real results happen.

Want someone checking the pages you don’t have time to?

That’s most of what a retainer is. Let’s talk about what it would look like for your site.