This week I found something slowing down my own website, and it wasn’t any of the usual suspects. The images were fine. The hosting is good. The culprit was a tracking plugin: the Facebook pixel (now called the Meta pixel) was quietly stopping my site’s cache from working on every single visit.
While I was digging, I also found Google Analytics loading twice on every page. Same data, double the weight.
Neither problem was visible from the outside. The site looked perfectly normal. If you run ads or have any kind of tracking on your website, there’s a fair chance something similar is happening to you, so here’s what I found, what I changed, and how you can check your own site in a few minutes.
What a page cache does (in plain English)
Most small business websites run on WordPress. Every time someone visits a page, WordPress has to build that page from scratch: pull the text from the database, run the plugins, put the layout together and send it to the visitor’s phone. That takes time, often a second or more.
A page cache fixes this. The first time a page is built, your hosting saves a finished copy. The next visitor gets that saved copy straight away, and the page appears almost instantly. Good hosts like SiteGround do this automatically.
There’s one catch. A cache will only hand out a saved copy if it’s sure the page is the same for everyone. If the page tries to set a cookie for the visitor, the cache assumes that page is personal to them and plays it safe by building a fresh one every time.
How the Facebook pixel was slowing down my website
The Facebook pixel plugin on my site was setting a tracking cookie from the server on every page it sent out. That’s exactly the signal that tells a cache “don’t use the saved copy for this one”.
So every visitor, on every page, was waiting for WordPress to build the page from nothing. When I measured it, the server was taking anywhere from 0.7 seconds up to 3 seconds just to start sending the page. That’s before a single image or line of text appears on screen.
Three seconds doesn’t sound like much until you’re the one looking at a white screen on your phone in a car park. Most people give up long before that and tap back to Google, where your competitor is one tap away.
I wasn’t running any Facebook ads, so the fix for me was simple: I switched the plugin off. The cookie disappeared, the cache started doing its job, and pages now start arriving in about 0.2 seconds.
Google Analytics was loading twice
The second problem was a classic case of two tools doing the same job. Google Analytics was being added to the site by Google’s own Site Kit plugin, and again through Google Tag Manager. Both were sending the same visits to the same Analytics account.
The extra copy was around 200 KB of code that every visitor’s phone had to download and run. On a mid-range mobile, that alone kept the browser busy for 300 to 400 milliseconds, during which the page can feel frozen when you try to scroll or tap.
This happens a lot. Someone sets up Analytics one way, a few years later another person (or another plugin) adds it a different way, and nobody notices because the reports still work. I kept Site Kit, removed Tag Manager, and moved the one small thing Tag Manager was doing (counting clicks on the WhatsApp button) into Site Kit instead. Same data, half the weight.
The results
Along with a couple of smaller fixes (including some leftover settings from an old caching plugin that were also telling the cache not to store pages), here’s how the site’s Google PageSpeed Insights scores changed:
- Mobile: 67 up to 89
- Desktop: 80 up to 95
- Server response: 0.7 to 3 seconds down to about 0.2 seconds
- Time the page felt “stuck” on mobile: 500 milliseconds down to 50
No redesign, no new hosting, no new plugins. Just taking away things that were getting in the way.
How to check if tracking is slowing down your website
You don’t need to be technical for the first two checks. The third one takes a little more poking around, but it’s worth doing.
1. Run your site through PageSpeed Insights
Go to pagespeed.web.dev, enter your homepage and look at the mobile result. Scroll down to the list of issues and look for anything about server response time, and for googletagmanager.com, facebook.net or connect.facebook.net appearing in the JavaScript lists. Tracking scripts showing up near the top of those lists is a good sign they’re costing you speed.
2. Check whether Google Analytics is added more than once
Open your website in Chrome, right-click anywhere and choose “View page source”. Press Ctrl+F (Cmd+F on a Mac) and search for G- followed by the start of your Analytics ID, then search for gtm.js. If your Analytics ID is loaded directly and you also have a Tag Manager container, there’s a good chance you’re tracking everything twice. Google’s free Tag Assistant tool will confirm it.
3. See if your pages are setting cookies
Open a private (incognito) window in Chrome so you’re not logged in, then press F12 to open the developer tools and click the Network tab. Load your homepage and click the very first item in the list (the page itself). Under Response Headers, look for a line called set-cookie.
A normal visitor landing on a normal page shouldn’t be sent a cookie by the server. If you see one, especially with a name like _fbp, your cache may be skipping that page for everyone. Reload the page a few times and click the Timing tab: if “Waiting for server response” stays above half a second every time, the saved copy probably isn’t being used.
What if you actually use the Facebook pixel for ads?
Then don’t just switch it off, because your ad reporting depends on it. The goal is to keep the tracking but stop it from breaking your cache. Usually that means loading the pixel in the visitor’s browser (where it can set its own cookie without touching the server) rather than through a plugin that sets the cookie on the server side, or adjusting the plugin’s settings so it doesn’t. After any change, check in Meta Events Manager that your events and conversions are still coming through.
The same goes for Google Ads conversions. When I removed the duplicate Analytics, I checked that enquiry and WhatsApp conversions were still reaching Google before calling it done. Speed is great, but not if it quietly breaks the numbers you use to make decisions.
If you’d like more background on why speed matters so much for local businesses, I covered that in how website speed impacts your business in Kildare.
Why this kind of problem goes unnoticed
Websites pick up plugins and tracking codes over the years. A marketing agency adds one, a Google tool suggests another, a plugin update changes how something works. Each one seems harmless on its own. Nobody goes back to check how they all behave together, and because the site still looks fine, there’s no reason to.
That’s a big part of what I do in WordPress maintenance: not just updating plugins, but looking at what’s actually running on the site and whether it still needs to be there. If I found this on my own website, it’s very likely there’s something similar on yours.
Want me to check your website?
If you run a business in Kildare or anywhere in Ireland and you’re not sure whether tracking is slowing down your website, send me a message. I’ll check your tracking, your cache and your speed scores and tell you in plain English what I find. It’s free and only takes me a few minutes.
Get in touch here, or read more about my free website review.
Frequently asked questions
Does the Facebook pixel slow down a website?
It can, in two ways. The pixel’s script adds weight that every visitor’s browser has to download and run, and some plugins that add it also set a cookie from the server, which can stop your page cache from working. The second one usually does far more damage.
Is it bad to have Google Analytics installed twice?
Yes. It makes your pages heavier for no benefit, and depending on how it’s set up it can double-count visits and events, which makes your reports unreliable.
Will removing tracking plugins break my ads?
It can if the plugin is the only thing sending your conversions. Always check where your conversion tracking comes from before removing anything, and test that conversions still arrive afterwards.
What’s a good PageSpeed score for a small business website?
Aim for 80 or above on mobile and 90 or above on desktop. Don’t judge a change on a single run, as scores can move by 5 to 10 points between identical tests. Run it three times and take the middle result.