tagora
container audit

GTM-KDZ2BXN

This container ships 56 hand-written scripts (26 KB of JavaScript) to every visitor — more than 90% of the 46,522 containers we have measured. That is an application's worth of code, delivered as tag configuration.

Tags212
Custom scripts56
Third parties18
Delivered715 KB
Versions110

What we observed

A real browser loaded rentalcars.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 — Google
Measurement sent to google-analytics.com — Google
Consent OneTrust answered its own API. no new hosts appeared after granting — either the tags are ungated, or they fire regardless and record the decision. Google recorded gcs=G111 (all granted).
Third parties contacted 23 hosts — cars-web-ccj.bstatic.com, cdn.rcstatic.com, t-cf.bstatic.com, cf.bstatic.com, cdn2.rcstatic.com, www.booking.com, cdn.cookielaw.org, securepubads.g.doubleclick.net, and 15 more
dataLayer events seen gtm.js, OneTrustLoaded, OptanonLoaded, gtm.dom, gtm.load, OneTrustOptionsSelected

Where the data goes

Not observed — on the page we loaded, measurement went to Google and nowhere else. observed on rentalcars.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.

reviewUniversal Analytics tags still shipped (77)
77 Universal Analytics tags are still in the container.

WhyUniversal Analytics stopped processing data in July 2023. These tags still download and execute on every matching page, and send to an endpoint that discards them.

CheckNothing is being collected from these. Confirm the equivalent GA4 tag exists, then delete them.

Seenseen in 23.2% of 46,522 containers measured

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

reviewHardcoded http:// URL (3)
3 pieces of custom code reference a plain http:// address.

WhyOn an https:// page the browser blocks or upgrades these. Blocked means the tag quietly stops working; upgraded only works if that host also serves https.

CheckCheck whether the hosts below still respond over https, and update the URLs.

Seenseen in 12.8% 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 (2)
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

reviewSame GA4 property configured more than once (1)
G-EGZ37KH61H is configured by 2 separate tags.

WhyEach config tag initialises the property independently, so a single page view can be counted once per tag. Sessions, users and conversion rates all inherit the error.

CheckIf more than one of these fires on the same page you are double-counting. Compare against a known-good day, or check for a step change in traffic when the second tag was added.

Seenseen in 4.8% of 46,522 containers measured

infoOne variable that a great deal depends on (73)
"affiliateCode" is read by 73 tags and triggers — more than anything else in this container.

WhyGTM shows you where a variable is defined, never how much depends on it. Editing this one touches a large share of the container at once, and whatever breaks will surface somewhere that looks unrelated to the change.

CheckBefore changing it, check what reads it. If it feeds both measurement and consent or routing logic, split those uses apart first.

Seenseen in 10.1% of 46,522 containers measured

infoLoads JavaScript from another host (8)
8 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

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.booking.com ×6analytics.skyscanner.net ×4www.facebook.com ×3secure.afilio.com.br ×2t.skyscnr.com ×2www.kayak.com ×24559546.fls.doubleclick.net ×15025602.fls.doubleclick.net ×1aff.bstatic.com ×1connect.facebook.net ×1es.beruby.com ×1is.accesstrade.net ×1neural27.cdnwebcloud.com ×1p.afilio.com.br ×1s.yimg.com ×1www.travelsupermarket.com ×1www.worldticketcenter.nl ×1с13.travelpayouts.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_32549216_1153 private injects code from cookie-cdn.1trust.app, cdn.cookielaw.org, cdn-ukwest.onetrust.com, cookie-cdn.cookiepro.com, cdn-au.onetrust.com, cdn-apac.onetrust.com · runs page-level globals
__cvt_32549216_1004 private injects code from x.rokt.com

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.

rentalcars.com

What this audit describes

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

ContainerGTM-KDZ2BXN
Published version110 — the identity of this configuration. It changes only when someone publishes.
Read at2026-08-12 22:23:45 UTC (3 months ago)
Sourcehttps://www.googletagmanager.com/gtm.js?id=GTM-KDZ2BXN
Body checksum980b487e28dad12bcf25ae9863283f4a172d5c2ce44e85e4137d7f6a5a621e79
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 3 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-KDZ2BXN

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