container audit
GTM-MWCHK79
86 tags, 17 custom scripts, 10 third-party hosts — an ordinary container, near the middle of what we measure (median: 39 tags, 4 custom scripts).
- 17 custom HTML tags carrying 30 KB of JavaScript — more than 70% of the 46,522 containers we have measured. This runs on every page the container loads on.
- 10 third-party hosts reachable from its tags — more than 80% of the 46,522 containers we have measured.
duplicate-ads-conversionis uncommon — under 4% of the containers we have measured have it. That is context rather than a verdict: a server container is rarer still and is a sign of a mature setup. What it means is in the finding itself.
Tags86
Custom scripts17
Third parties10
Delivered589 KB
Versions193
What we observed
A real browser loaded glgresearch.com 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
googletagmanager.com — GoogleMeasurement sent to
google-analytics.com — GoogleConsent
OneTrust answered its own API. 3 measurement hits left the page before it was granted, carrying a client id (whether that is permitted depends on jurisdiction, and this was not a European visit). no new hosts appeared after granting — either the tags are ungated, or they fire regardless and record the decision. 4 advertising hosts were contacted before anything was granted.
Third parties contacted
25 hosts — cdn.prod.website-files.com, cdn.jsdelivr.net, cdn.cookielaw.org, d3e54v103j8qbb.cloudfront.net, cdnjs.cloudflare.com, unpkg.com, success.glginsights.com, marketo.use1-marketplace-1p-apps-prod-red.if.webflow.services, and 17 more
dataLayer events seen
gtm.js, OneTrustLoaded, OptanonLoaded, gtm.dom, gtm.load, gtm.scrollDepth, marketo.loaded, gtm.click
Where the data goes
Not observed — on the page we loaded, measurement went to Google and nowhere else. observed on glgresearch.com 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 (3)
3 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
reviewWrites cookies directly (2)
2 pieces of custom code set cookies in code.
WhyCookies set this way bypass GTM's consent settings, because the consent checks live in the tag templates rather than in raw JavaScript.
CheckIf any of these cookies are used for analytics or advertising, confirm they are still gated on a consent decision.
Seenseen in 21.2% of 46,522 containers measured
reviewSame Google Ads conversion defined more than once (1)
1 conversion action is defined by more than one tag.
WhyA conversion ID plus label identifies one action. Two tags carrying the same pair can report the same conversion twice, inflating conversion counts and the ROAS that bidding runs on.
CheckCheck whether both tags can fire on the same page. If they can, your Ads reporting is overstating this action and automated bidding is optimising against it.
Seenseen in 3.8% of 46,522 containers measured
infoLoads JavaScript from another host (6)
6 pieces of custom code fetch and run JavaScript from another host.
WhyWhatever that host serves executes with full access to the page — it can read the DOM, cookies and form fields. The code is not in this container, so it can change at any time without any change here.
CheckConfirm you recognise every host below and that someone owns the relationship. A host you cannot name is the one to chase.
Seenseen in 54.4% of 46,522 containers measured
infoConsent configuration detected (2)
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
infoUses browser storage (1)
1 piece of custom code read or write localStorage or sessionStorage.
WhyBrowser storage persists across visits and is not covered by cookie consent tooling, so it is easy to overlook when auditing what you keep on a visitor's device.
CheckConfirm nothing personal is being kept there, and that it is covered by your privacy notice.
Seenseen in 23.3% 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 »
www.google-analytics.com ×11www.googleadservices.com ×10vimeo.com ×4connect.facebook.net ×3www.facebook.com ×3cdn.c360a.salesforce.com ×1googleads.g.doubleclick.net ×1www.clarity.ms ×1www.vimeo.com ×1www.youtube.com ×1
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_30741981_119 private runs page-level globals__cvt_30741981_219 private injects code from s.yimg.jp · runs page-level globals__cvt_30741981_221 private injects code from s.yimg.jp · runs page-level globals__cvt_30741981_223 private injects code from s.yimg.jp · runs page-level globals__cvt_30741981_227 private injects code from s.yimg.jp · runs page-level globals__cvt_30741981_229 private injects code from s.yimg.jp · runs page-level globals__cvt_30741981_235 private injects code from snap.licdn.comDetected 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.
What this audit describes
Containers change. These findings describe one specific artifact, and you can re-fetch it to check this reading.
| Container | GTM-MWCHK79 |
|---|---|
| Published version | 193 — the identity of this configuration. It changes only when someone publishes. |
| Read at | 2026-08-23 17:49:48 UTC (2 months ago) |
| Source | https://www.googletagmanager.com/gtm.js?id=GTM-MWCHK79 |
| Body checksum | d6b3ba8120acf61e506c8ef2924540f0dd7a56e8e115c0158a7b67e64ee8e7e4Evidence 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.
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 »