Analytics rarely breaks with a bang - it breaks silently. A theme update, a new consent banner, a developer removing "unused" scripts, and suddenly your purchase tag is gone. Here's how to catch it on day one instead of next quarter.
Tracking almost never breaks with a bang. It breaks silently - a deploy strips a tag, a developer renames a CSS class your trigger depended on, a consent banner update blocks a pixel - and nothing turns red. Your dashboards just quietly go empty and you find out weeks later when the numbers look wrong and you've already wasted ad spend optimising on missing data. This guide covers how to monitor website tracking so you catch the break in hours, not weeks.
Home, a key product/category page, and the checkout or thank-you page - the ones where the money actually gets tracked. Daily is a good baseline; higher frequency around a release.
Tags are injected at runtime by GTM, the CMS and consent tools. Only a rendered page shows what really fires - a raw HTML fetch will miss most of it and give false alarms.
Confirm the events still carry value, currency and transaction_id. A purchase that fires with value=0 is "working" and still broken.
Fire an alert when something goes from working to broken (and when it recovers) - not on every run. Daily "all good" emails train you to ignore them, so the one that matters gets missed too.
Yes - and for one or two sites it's a reasonable project. The shape of it:
duckmetric does exactly this out of the box: scheduled re-scans in a real browser, checking both that tags fire and that the data inside is intact, with alerts via email, Slack or Microsoft Teams the moment a tag goes from firing to broken - and only on the change, so there's no daily noise.
Continuously monitor the money pages (checkout, key conversions) at least daily, and run a fuller audit around any site release. Tracking breaks most often on deploys, so tie a check to your release process.
GTM and the ad platforms don't tell you when a tag stops firing - there's no built-in "tag missing" alarm. That's exactly the gap a monitor fills: something has to load the page and confirm the request still goes out.
Yes. A monitor watches the requests the page makes from the outside, so it needs no code change. You only need edit access if you want to fix what it finds.
A change from working to broken - a previously-firing tag that stops, an event that loses its value/currency/transaction_id, or a tag that starts firing before consent. Alert on the transition, not on every scan.
Related: how to check GTM tracking · monitoring & alerts · full tracking audit
See your tracking today, then put the pages you can't afford to lose under monitoring.