Connecting GA4 and Google Optimize

February 03, 2022 - Written by

Just yesterday afternoon, while I was browsing the Google Analytics 4 Demo account, I noticed the presence of some “special” events and I reported everything via Twitter and LinkedIn.

After a few hours, thanks again to a tweet from Charles Farina, I see that my intuition has been confirmed: GA4 and Google Optimize can finally be integrated!

This is great news as it is another piece that composes the puzzle of the total integrations of the Google Marketing Platform ecosystem even for “standard” GA4 users and not just for 360 Google accounts.

Let’s see the details of the latest integration.

Connecting GA4 and Google Optimize

First you need to log in to your Google Optimize account (or create a new one) and click “Settings” at the top right, as shown in the screenshot below

In the screen that opens, select the slot dedicated to Google Analytics (step 2)

And then modify the link from Universal Analytics to the GA4 property of interest (step 3) and save the change.

First Considerations

What is immediately evident is the impossibility of sending the data to two distinct properties, namely that of Universal Analytics -maybe- “historical” and the new one of GA4.

Once the change has been made, we therefore make a break with the past as all any drafts and new experiments will be updated with the link to the GA4 property. The tests that we have instead concluded and that were under Universal Analytics property will keep the existing link and the data will be accessible as long as the UA property exists and / or you have the viewing grants (or higher).

The counting of impressions will start populating up to 12 hours after the start of an experiment.

First suggestion: if you want to do the tests first, create a new Google Optimize account to link a test GA4 property to and then switch to the “live” version: you will have time to become better acquainted with the new events generated by Optimize.

Main news for GA4 integration and Google Optimize

Obviously there are also many news (and benefits) in the field of GA4 – Google Optimize integration, let’s see the most relevant.

GA4 Audiences in Google Optimize

Optimize allows you to use GA4 audiences in your experiments, in order to better target your experiments to a group of users who exhibit certain behaviors on your site.

This function, in Universal Analytics, was only active for 360 accounts, now it is available to all GA4 properties.

Given the improvement in audiences in GA4, think about what can be achieved in terms of targeting users and the infinite possibilities for improving the site’s performance and the revenue at last!

Simultaneous activation of experiments

At the moment you can activate up to 10 experiments and 10 simultaneous customizations per property.

Compared to Universal Analytics this is a slight downgrade as previously the limit was 24 experiments and 10 simultaneous customizations per view.

I am quite certain, however, that after an initial adjustment phase there will be an upgrade of the experiments and customizations at the same time.

Unlike Universal Analytics, these features are not yet available in GA4 .. 🙁


Compared to the goals in UA, in GA4 it is possible to choose at the moment between Purchases, Purchases Revenue and Pageviews

Variant Impressions

In GA4 we will find the default optimize_personalization_impression and experiment_impression events in the reports when we activate an experiment or a customization in Google Optimize (see next chapter).

Experiment Duration

The duration of the experiment is reduced from 90 days max of UA to 35 days of GA4

Variation in the data collected

Also at the reporting level, there are some differences compared to UA:

  • In GA4 we can generate reports on individual users and on their behavior in the experiences in multisession mode
  • Optimize is not currently expected to release a realtime report but we can always use GA4 realtime report to view impressions
  • At the moment, custom dimensions related to experiments are not populated as in Universal Analytics
  • It may take up to 72 hours to display data within Optimize once the GA4 is connected

What data do I find in GA4?

I think this is one of the main questions at the moment that a user asks himself before generating the switch in the integration between GA4 and Google Optimize.

  • Among the recorded events I will find experiment_impression or optimize_personalization_impression. The screenshot below shows the data relating to an Optimize experiment in GA4:
  • Among the parameters related to the event I will find experiment_id which indicates the id of the active experiment
  • Within the “Explore” section I can use the data relating to the generated experiment

Overall GA4 and Google Optimize integration considerations

The integration between GA4 and Google Optimize brings GA4 itself to an increasingly important level in terms of improving both user experience and performance.

First of all it is now possible to use audiences for all GA4 properties. That is, we can target users who need to be involved in the experiences we are creating in a super precise way. This obviously also translates into a benefit in relation to advertising for the remarketing and retageting, since the same audiences can be imported into Google Ads.

I’m sure that new features will be added to this link shortly .. in the meantime, let’s get started and increase the performance of our business!

Comments 2 Replies to “Connecting GA4 and Google Optimize”
    • Maybe your account GA4 is under “organization” and Optimize not or viceversa.
      You must have both account under the same organization otherwise you cannot see them

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