How to Audit Your WordPress GA4 Setup for Broken Event Tracking
Before you touch a headline or a button colour, it’s worth checking whether your analytics are even telling you the truth. I’ve lost count of the sites I’ve audited where the enquiry numbers in GA4 didn’t match reality, either counting nothing at all or counting the same submission twice.
Why this comes before anything else
If a page looks like it’s converting badly, the instinct is usually to fix the page. But if the tracking underneath it is broken, you’re optimising against numbers that were never accurate in the first place.
I’ve seen a client convinced their contact page was underperforming for months, when the real issue was a duplicate GA4 tag inflating every other page’s numbers and making the contact page look worse by comparison than it actually was. Fixing the tracking took twenty minutes. It would have taken a lot longer to notice if we’d just kept tweaking the page instead.
Check the installation first
Open your site in an incognito window, right click, and view the page source. Search for “G-” followed by a string of characters; that’s your GA4 measurement ID.
If you find it appearing more than once, or if you find two different measurement IDs on the same page, you’ve likely got a duplicate install. This usually happens when one is added manually in your theme’s header, and another is added again through a plugin like Rank Math, Site Kit, or a dedicated analytics plugin.
Duplicate tags mean duplicate events. This means every conversion in your reports could be counted twice without anything visually looking wrong on the page itself.
Using Tag Manager’s preview mode properly
If you’re managing tags through Google Tag Manager rather than pasting GA4 code directly into your theme, preview mode is where the real diagnostic work happens. Open GTM, click preview, and enter your site’s URL. This opens your actual site with a debug panel attached, showing you every tag firing in real time as you interact with the page.
Submit a real test enquiry through your form while watching that panel. You’re looking for two things. First, does your conversion event actually fire at all when the form succeeds? If nothing shows up in the panel at the moment of submission, that’s your answer right there: GA4 was never told the conversion happened.
Second, does the event fire exactly once? If you see the same event listed twice in the space of a second, that’s a duplicate trigger. This usually occurs because a form plugin’s own built-in tracking and a separate GTM trigger are both watching for the same submission and both firing.
The specific things that usually cause this
The most common cause I’ve found on WordPress sites is a mismatch between how the form actually submits and how the tracking trigger is set up to detect success. A lot of GTM setups use a “Page View” trigger pointed at a thank you page URL, which works fine if the form does a full page reload on submission.
Plenty of modern form plugins submit through AJAX instead, meaning the page never actually reloads and that URL-based trigger simply never fires, even though the form worked perfectly from the visitor’s side.
The fix there is switching the trigger from a destination URL to a specific element, usually the success message the form plugin injects into the page once submission completes, or a custom JavaScript event the plugin fires that GTM can listen for directly. Most form plugins document what that success indicator actually is; it’s just rarely the first thing anyone thinks to check.
The second common cause is a plugin doing its own GA4 push behind the scenes. A form plugin, an SEO plugin, or a caching plugin with a built-in analytics feature running alongside a separate manual GTM setup nobody remembered was already there will cause major discrepancies. Neither one is wrong on its own, they just don’t know about each other, and the result is the duplicate firing described above.
Cross checking against real numbers
Once you think you’ve found the issue, don’t just trust the preview panel; check it against something you can count by hand. Submit three test enquiries over a day and see whether GA4 reports three conversions, not six, and not zero.
If you’re using a CRM or an email inbox that also logs enquiries, compare that count against what GA4 is showing for the same period. A gap between the two is the clearest possible sign that something in the tracking chain is still broken, even after you think you’ve fixed it.
What this actually sets up
Fixing broken event tracking doesn’t improve your conversion rate on its own; it just means the number you’re looking at is finally real. But that’s the whole point. Every other fix on this site, speed, form friction, layout shift, only makes sense to prioritise once you can actually measure whether it worked.
If your GA4 setup is still counting double or missing conversions entirely, none of those other fixes will show up clearly in your data even if they’re genuinely working.
This is the first piece of the structural conversion architecture I cover under Fix Conversions, alongside the form and layout diagnostics that come after it. My private practice is currently at full capacity, but you can check my current availability or join the waitlist on the enquiry page.