Learn · How-To

How to Connect GA4 to Google Tag Manager

This is where most published GTM tutorials are now wrong. The GA4 Configuration tag they tell you to create has been replaced by the Google tag, and Google states that existing GA4 configuration tags are automatically upgraded to it. If you go looking for the old tag type you will not find it, and if you follow a guide written before the change you will spend an hour confused. This guide uses the current setup, and explains the one distinction that matters afterwards: Tag ID versus Measurement ID.

1. 1

   Create the GA4 property and web data stream first

   In Google Analytics, create a property for the site and add a web data stream for the domain. The data stream is what produces the identifier you will need in Tag Manager. Set the timezone and currency now, because changing them later does not retroactively fix historical data.

2. 2

   Note the difference between Tag ID and Measurement ID

   The Google tag uses a Tag ID, which can connect to multiple destinations. GA4 Event tags use the Measurement ID, and their events go only to that specific GA4 data stream. Confusing the two is the most common reason events arrive at the wrong property or nowhere at all.

3. 3

   Create a Google tag in Tag Manager

   In your container, create a new tag of type Google tag and give it your Tag ID. Trigger it on All Pages. This is the tag that loads Google tracking on your site; everything else builds on it. There is no longer a separate GA4 Configuration tag to create.

4. 4

   Use settings variables rather than hunting for Fields to Set

   The old Fields to Set section has been replaced by two reusable variables. A Configuration settings variable holds parameters loaded when the Google tag loads. An Event settings variable holds additional parameters sent with each event. If a guide tells you to use Fields to Set, it predates this change.

5. 5

   Preview and confirm the tag fires

   Open Preview mode, load your site, and confirm the Google tag fires on page load. Then open GA4 Realtime and confirm your own visit appears. Two checks, not one — a tag that fires in GTM but produces nothing in GA4 usually means the wrong identifier.

6. 6

   Confirm your own traffic is excluded

   Set up internal traffic filtering in GA4 so your own visits do not pollute the data. On a low-traffic B2B site this is not a nicety. Your own team can easily be a double-digit percentage of recorded sessions, which makes every subsequent number misleading.

7. 7

   Check that referrals and cross-domain settings are right

   If you use a separate booking, payment or subdomain system, configure cross-domain measurement so a visitor moving between them is not counted as two sessions from a referral. This single setting explains a great many inflated session counts.

8. 8

   Publish and then verify in a clean browser

   Publish the container version, then load the site in a normal window and confirm data still arrives. Preview mode runs against a draft, so an unpublished container produces a perfect test and no live data.