When a store owner tells me "our ad results don't match our Shopify orders", the problem is almost always in how the tracking was set up. I audit and fix web pixels for Shopify stores, and the same issues come up again and again. Below are the 7 problems I find most often, and the signs that tell you your store has them.
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1. Too many pixels on one store #
It's common to find several Google Analytics tags, more than one Meta (Facebook) Pixel, Google Ads tags, TikTok, Pinterest and other pixels all running on the same store, some added by apps, some pasted into the theme, some loaded through Google Tag Manager.
Every pixel adds code that runs in your visitor's browser, and when several of them track the same thing, it's hard to know which numbers to trust.
Signs this is happening on your store:
- In Shopify admin under
Settings → Customer events, you see pixels you don't recognize. - Browser extensions like Google Tag Assistant or Meta Pixel Helper show more than one ID for the same platform.
- Different reports show different numbers for the same thing.
Why it costs you sales: You make marketing decisions on numbers you can't trust, and every extra pixel slows your store down a little more.
2. Old pixels left behind after changing agencies #
This is one of the most common causes. A store works with one agency or freelancer, then moves to another. The new team adds their own tracking setup, but the old one is never removed. After a few changes, the store has layers of tracking from people who no longer work on it.
Signs this is happening on your store:
- You've changed agencies, marketers or developers in the past.
- There's tracking code in your theme or in GTM that nobody on your current team set up.
- You still see tags for ad accounts or analytics properties you no longer use.
Why it costs you sales: Old pixels can send your store's data to accounts you don't control, double-count events, and slow down every page.
3. The same event fires twice #
When tracking is added in more than one place (an app, the theme and GTM, for example), the same event can be sent twice. The most damaging case is a purchase counted twice: your reports show more sales than you actually made, and your ad platforms think a campaign is working better than it is.
Signs this is happening on your store:
- GA4 or Meta shows more purchases than your Shopify orders.
- Add-to-cart or checkout events look unusually high.
- Your return on ad spend looks great in the ad platform, but not in your actual revenue.
Why it costs you sales: Ad platforms optimize your budget based on these events. Wrong data means your money goes to the wrong campaigns.
4. Extra GTM scripts just to send custom events #
Many stores want to track custom events, like a quiz completion, a specific button click, or a purchase sent to GA4 for their paid ads. A common setup is to inject Google Tag Manager into the theme and then add more scripts on top to push those events.
In many cases, this extra layer isn't needed. Shopify's Customer Events lets you set up custom pixels directly in Shopify admin and send the events straight to GA4, including checkout and purchase events. It's cleaner, it follows Shopify's current setup, and it means one less script loading on every page.
Signs this is happening on your store:
- GTM is pasted into your
theme.liquid, and custom events depend on scripts added in the theme. - Your tracking needs a developer every time the theme changes.
- Checkout or purchase events are missing or unreliable in GA4.
Why it costs you sales: Extra script layers slow down the store and break easily, so you lose tracking right when you need it most.
5. Tracking that broke when checkout changed #
Shopify has moved checkout, the Thank you page and the Order status page to checkout extensibility. The old ways of adding tracking scripts to these pages, like checkout.liquid and "additional scripts", no longer work. Stores that relied on them can lose purchase tracking without noticing, because the rest of the store still looks fine.
Signs this is happening on your store:
- Purchase or checkout events dropped suddenly in GA4 or your ad platforms.
- Your tracking was set up years ago and hasn't been checked since Shopify's checkout changes.
- Conversion tracking for Google Ads or Meta shows fewer conversions than your orders.
Why it costs you sales: If purchases aren't tracked, your ads can't learn who buys, and your campaigns get worse over time.
6. The Meta (Facebook) Pixel set up the hard way #
The same problems happen with the Meta Pixel. It's often hard-coded into the theme, added again by an app, and sometimes loaded through GTM too. Purchases are counted twice, or not at all after checkout changes.
For most Shopify stores, the better setup is Meta's official Facebook & Instagram channel connected to your store, with one pixel and the Conversions API, and no duplicate copies in the theme or GTM.
Signs this is happening on your store:
- Meta Pixel Helper shows the pixel firing more than once, or shows more than one pixel ID.
- Meta Events Manager warns about duplicate events or low event match quality.
- Your Meta purchase numbers don't match your Shopify orders.
Why it costs you sales: Meta's ads depend heavily on accurate purchase data. Bad tracking means higher costs and weaker results.
7. Everything runs in the browser #
Most tracking runs in the visitor's browser. Every pixel adds JavaScript that competes with your store for the visitor's phone, and browser privacy settings and ad blockers can stop some of it from working.
Server-side tracking sends the important events, like purchases, from the server instead of only from the browser. Examples are Meta's Conversions API and server-side setups for Google. Because less code runs in the browser, it has less impact on your store's front-end speed, and the data is usually more complete.
Signs this is happening on your store:
- All of your tracking is browser-based (pixels and tags only).
- Your ad platforms report fewer conversions than your actual orders.
- PageSpeed Insights shows tracking and marketing scripts in "Reduce the impact of third-party code".
Why it costs you sales: You pay for tracking twice: once in slower pages, and again in missing data.
Read more: Why is my Shopify store so slow? 9 causes I find in speed audits →
What clients say about this kind of work #
“Philip is always a pleasure to work with. This was my second project with him. His dev skills are exceptional and I look forward to working with him again.”
“Philip is excellent, as always. Phenomenal developer and a must-have for any team.”
