container audit

GTM-7NMH

44 tags, 13 custom scripts, 1 third-party host — an ordinary container, near the middle of what we measure (median: 39 tags, 4 custom scripts).

13 custom HTML tags carrying 5 KB of JavaScript. This runs on every page the container loads on.
1 third-party host reachable from its tags.
Measurement runs through a server container on its own domain — the mark of a mature setup, and rarer than the tooling vendors imply.

Tags44

Custom scripts13

Third parties1

Delivered494 KB

Versions152

What we observed

A real browser loaded firstclasswatches.co.uk 2 months ago and recorded every request it made. This is what happened, as distinct from what the container is configured to do. It is one page load — anything that fires only deeper in the site did not fire here.

Container loaded from oso.firstclasswatches.co.uk — the site's own host

Measurement sent to google-analytics.com — Google

The container is self-hosted; the measurement still goes to Google. The first-party path that a tagging server provides is not being used for the data itself.

Consent a consent platform is present, but our browser could not complete the accept step — so the before-and-after comparison did not run here. 2 hosts appeared only after consent was granted. Google recorded gcs=G100 (all denied).

Third parties contacted 18 hosts — js.klarna.com, geoip.cookieyes.com, book.timify.com, gepi.global-e.com, www.mczbf.com, web.global-e.com, globale-analytics-sdk.global-e.com, bat.bing.com, and 10 more

dataLayer events seen gtm.js, gtm.dom, ga4_view_item_list, gtm.scrollDepth, gtm.load

Where the data goes

Not observed — on the page we loaded, measurement went to Google and nowhere else. observed on firstclasswatches.co.uk More info »

Findings

Ordered by consequence. review has a concrete cost when it bites; info is real but depends on your setup. Seen is how common it is across the containers we have measured — reported separately on purpose, because common and harmless are different claims.

reviewdocument.write (2)

2 pieces of custom code call document.write.

Whydocument.write blocks the HTML parser while it runs, and browsers ignore it entirely once the page has finished parsing — so an async-loaded tag using it can silently do nothing.

CheckIf these tags fire on page load they are costing render time; if they fire later they may not be working at all. Worth confirming the tag still does what it was added to do.

Seenseen in 18.4% of 46,522 containers measured

infoConsent configuration detected (3)

The container declares one or more consent signals.

WhyConsent handling is present in the container. This describes what the artifact declares; what actually happened on the page is measured separately, above.

CheckConfirm these settings match the consent policy you intend to enforce, and compare them with the before-and-after observation.

Seenseen in 44.6% of 46,522 containers measured

infoVendor IDs written into custom code (1)

1 vendor ID is pasted directly into custom HTML rather than held in a variable or template.

WhyChanging a property, pixel or account then means editing every tag that mentions it, and any one that gets missed keeps sending to the old destination indefinitely.

CheckFine if the ID never changes. If you have ever migrated a property, check that none of these still point at the old one.

Seenseen in 31.4% of 46,522 containers measured

Third parties it can reach

Each host is a party that can execute code or receive data in a visitor's browser. Follow one to see who else loads it. More info »

static.cloudflareinsights.com ×2

What the custom templates can do

Custom templates are third-party code shipped inside the container. Injecting scripts and running page globals is ordinary for them — most tag templates need it to work — so this is an inventory, not a warning. It lists the capability each template declares so you can match it against templates you meant to install.

__cvt_MQDKZ gallery injects code from www.clarity.ms · runs page-level globals

Detected on

Sites observed loading this container. A container used across many hosts is a shared template; one on a single host is a bespoke build. Follow a site to see every container it loads.

firstclasswatches.co.uk firstclasswatches.com

What this audit describes

Containers change. These findings describe one specific artifact, and you can re-fetch it to check this reading.

Container	`GTM-7NMH`
Published version	`152` — the identity of this configuration. It changes only when someone publishes.
Read at	2026-08-23 17:34:25 UTC (2 months ago)
Source	`https://www.googletagmanager.com/gtm.js?id=GTM-7NMH`
Body checksum	`0fda571f0cefee489859435b95d81b0e90fa2be16f3ddfba72ff4851bd48548b` Evidence of the exact bytes we read, not an identity: Google varies the response per request, so re-fetching an unchanged container yields a different checksum. Compare the published version instead.

Re-audit

This reading is from 2 months ago. A container can be republished at any time, and nothing here updates on its own — a fresh read is the only way to know whether it still says this. Running it again replaces this page in place, so the link keeps working.

Re-audit GTM-7NMH

Check another container

Put this container under version control. Tagora exports it to a repository you own, so every change arrives as a pull request. How it works »