container audit
GTM-M6JVWR
This container can hand execution to 13 third parties — more than 90% of the 46,522 containers we have measured. Each serves code it controls, which can change at any time.
- 13 custom HTML tags carrying 10 KB of JavaScript. This runs on every page the container loads on.
inner-htmlis uncommon — under 6% 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.
Tags44
Custom scripts13
Third parties13
Delivered508 KB
Versions173
What we observed
A real browser loaded flysafair.co.za a month 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
www.flysafair.co.za — not Google, at /bz5q/ag/g/cMeasurement is first-party; the container still loads from Google. These are separate decisions, and this is the more common of the two.
Forwarded to
GA4 ×3 — read from the measurement id, not the hostname
Consent
a consent banner was present and we accepted it. 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). 2 hosts appeared only after consent was granted. 6 advertising hosts were contacted before anything was granted.
Third parties contacted
21 hosts — fonts.googleapis.com, www.datadoghq-browser-agent.com, zapper-ecommerce.s3.eu-west-1.amazonaws.com, api-production-safair-booksecure.ezyflight.se, www.googletagmanager.com, static.ads-twitter.com, connect.facebook.net, analytics.tiktok.com, and 13 more
dataLayer events seen
gtm.dom, gtm.scrollDepth, gtm.js, gtm.historyChange, gtm.historyChange-v2, gtm.click, gtm.load
Where the data goes
Confirmed — a browser watched this site send measurement data to www.flysafair.co.za, not to Google. observed on flysafair.co.za 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 (1)
1 piece 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 innerHTML (1)
1 piece of custom code assign to innerHTML.
WhyAssigning innerHTML parses the string as HTML. If any of it comes from the URL, the page or a cookie, that is a script-injection route into your own site.
CheckCheck whether the assigned value is a fixed template or built from something a visitor can influence.
Seenseen in 5.7% of 46,522 containers measured
reviewNo consent signal in the container (1)
Nothing in this container sets, reads, or gates on a consent state.
WhyThe container itself neither sets a Consent Mode default, holds any tag back for consent, nor references a known consent platform. Either enforcement lives entirely outside GTM — where it cannot be audited from here — or tags fire regardless of what a visitor chose.
CheckIf a consent platform blocks scripts before GTM loads, this is fine — confirm that is actually the case. If not, tags are firing on a choice nobody recorded.
Seenseen in 52.1% of 46,522 containers measured
infoLoads JavaScript from another host (2)
2 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
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 ×9images.prismic.io ×7www.googleadservices.com ×4affiliation.software ×1analytics.tiktok.com ×1app.viralsweep.com ×1connect.facebook.net ×1conversions.lunio.ai ×1dc.ads.linkedin.com ×1googleads.g.doubleclick.net ×1snap.licdn.com ×1webchat.notifications.stubber.com ×1www.facebook.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_2030928_125 private runs page-level globals__cvt_5D4TS gallery injects code from static.ads-twitter.com · runs page-level globals__cvt_PBZB3 gallery injects code from static.ads-twitter.com · runs page-level globalsDetected 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-M6JVWR |
|---|---|
| Published version | 173 — the identity of this configuration. It changes only when someone publishes. |
| Read at | 2026-08-12 22:27:57 UTC (a month ago) |
| Source | https://www.googletagmanager.com/gtm.js?id=GTM-M6JVWR |
| Body checksum | 19a0be4cd4120af9d6bdcf51c1cae4b4a2897181cc8d7819287d2227e1e25d07Evidence 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 a month 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 »