Free GTM checker: see the tags any website loads
Type a website. In a few seconds you see its Google Tag Manager containers, the GA4 and Google Ads IDs, the Meta pixel, the consent setup and any tag that loads twice.
What the GTM checker looks at
Tag Manager containers
Every GTM container the page loads, how many times, and whether it comes from googletagmanager.com or from a first-party or server-side host.
Duplicate tags
The same container loaded twice, and GA4, Google Ads or the Meta pixel set up both on the page and in Tag Manager: the usual cause of double page views and double purchases.
GA4 and Google Ads IDs
The measurement IDs (G-...) and Google Ads tags (AW-...) on the page and in the published version of each container.
Meta pixel
Pixel IDs set up on the page or in a container.
Consent mode
Whether the page sets a consent mode default, whether a consent template runs in the container, and which consent banner the site uses.
Leftovers
Universal Analytics tags still loading years after it stopped, and a high count of custom HTML tags worth a look.
From a quick check to a full GTM audit
This tool reads what anyone can see from outside. A complete GTM and GA4 audit needs the inside: every tag, trigger and variable, the consent settings of each tag, GA4's data streams and key events, and your key pages loaded in a real browser to see what actually fires. Tracking Whisper runs that audit with read access, explains each finding, and builds the fixes in its own workspace for you to approve. For a do-it-yourself version, follow the GTM audit checklist.
Questions
Is the GTM checker free?
Yes. There is no sign-up and no email. A visitor can run a few checks a minute, to keep the tool fast for everyone.
How does it find the tags?
It fetches the page's HTML the way a browser would, finds the Google Tag Manager snippets, gtag.js and the Meta pixel in it, then reads the published version of each GTM container from Google's public address, where the IDs and the kinds of tags in it can be seen.
Why does it miss a tag I know is there?
It reads the HTML the server sends and does not run the page's scripts. Tags added by a plugin after the page loads, tags behind a consent banner, and IDs kept in GTM variables or a server container are not seen. The full audit opens the page in a real browser and reads the container itself.
What does 'loaded twice' mean?
The same container, or the same GA4 or Ads tag, starts from two places. Each event is then sent twice, so page views, purchases and conversions are doubled in reports and in bidding.
Does it store the site I check?
The result is kept in the server's memory for ten minutes so the same check asked again is instant, then dropped. Nothing is saved to a database and no account is created.