Confirm it once
Scan a store. Four page types, a real browser, no account.
A GA4 alert cannot see a silent tag
A Google Analytics alert watches counts that arrived. It cannot see a library that returned 200 and never reached /g/collect. That is a different failure, and it is the common one.
| A GA4 custom alert | Tagnovo | |
|---|---|---|
| What it watches | Events that reached Google | Whether the collect request left the page |
| Library present, no event | looks like a quiet day | broken, if the control fired |
| Fires on home, silent on product | A smaller total, if you notice | A page-type matrix |
| A consent banner that never resolves | Fewer events, no cause | Unobservable, not broken |
| When it tells you | After enough events failed to arrive | After a second confirmed check agrees |
| Other vendors | Not in GA4 | Each vendor in the signature set |
When a GA4 alert is the right tool
If you want to know that purchase events dropped after a promo ended, watch the count in GA4. That is a business question, and Tagnovo will not invent a percentage decline for you. We report absence: the collect request stopped, or it never started on that page type.
The failure most shops actually have is quieter. The theme still lists the tag. The library still returns 200. No event leaves. Totals look plausible because another page still sends.How to tell if a pixel is actually working.
Then keep looking
Trace repeats the check so a silent week does not become a silent quarter.
Watch one store free
Daily checks, email when a second confirmed reading agrees. A GA4 alert watches counts that arrived. This watches whether the collect request left the page.