Skip to content
GetProfit
Log in

← All terms

Google Tag Manager (GTM)

Google Tag Manager is Google's tag management system, which lets a store add and change tracking tags on its site without editing the site's code.

How it works

You add two code snippets to every page once, then manage tags in the Tag Manager interface. A container holds tags (Google Ads, GA4, third-party), triggers that say when each tag fires, and variables that feed it values. For a store, the key trigger is the purchase event the site pushes into the dataLayer with the order number, amount and items (the purchase event in Tag Manager).

You make edits in a workspace, and they go live only when you publish the container. Each publish records a version you can go back to. Preview mode and Tag Assistant show which tags fire before you publish.

The Conversion Linker tag keeps the ad click details until the order; it isn’t needed when a Google tag loads on every page. Enhanced conversions send hashed customer data captured by the conversion tag.

Where you see it

  • tagmanager.google.com: the container, GTM- plus a code, with Tags, Triggers, Variables and Versions.

Example

Example store, not client data.

The tableware shop’s container fires a GA4 purchase event and a Google Ads conversion tag on the custom event purchase. Variables read the order number and the amount, 600.

Of 300 orders in a month, 12 buyers reload the confirmation page. A tag that fires on page load without the order number would count 300 + 12 = 312 purchases. With it, Google Ads drops the 12 repeats.

Not to be confused with

  • Server-side tagging — a container that runs on a server you control. A web container runs in the visitor’s browser.
  • Google tag gateway — serves the container from the store’s own domain; the tags stay the same.

Right and wrong readings

  • Wrong: “I changed the tag, so the site sends the new data.” Right: until you publish the changes, the site runs the previous version.
  • Wrong: “The tags are in Tag Manager now, so the old purchase tag in the theme can stay.” Right: both fire, so the same purchase can be sent twice.

Sources