How to smoothly migrate to Google Analytics 4?

Introduction

In April Google has officially announced to shut down Universal Analytics by July 2023, latest October 2023 for 360 accounts. Unfortunately, Google is not offering a data migration solution for switching to GA4. Consequently, the clock is ticking for managing a successful and smooth transition to GA4. Keep on reading to find actionable strategies for all sorts of setups, whether you have the classic client-side GTM setup or are already fully advanced with GTM server-side tagging.

How to Smoothly Migrate to Google Analytics 4?

It is most important to start the GA4 data collection process as soon as possible, preferably before July 2022, to ensure that a full year of data is available for reporting once Universal Analytics shuts down. That also gives you and all end-users enough time to understand and get familiar with the discrepancies between GA4 and Universal Analytics metrics. So far, Google is not providing any options to migrate data from Universal Analytics to GA4. Therefore, we recommend exporting all Universal Analytics data to BigQuery or to your DWH as soon as possible. This is to ensure that you have the historical data saved.

Depending on your resources there are two viable options for such a parallel infrastructure. Both are described below.

Short Term Implementation

No matter whether you have gtag.js directly implemented or you are using GTM client or server-side tagging, we recommend getting started as soon as possible by adding your two most basic GA4 events: page views and transactions. This way you are tracking every page view and transaction to both, your existing Universal Analytics and your new GA4 property.  In the image shown below you can see how a GTM client-side implementation will send out two hits per event, one to Universal Analytics and one to GA4.

Having the GA4 configuration tag and the purchase tag implemented ensures that you have the following metrics in GA4 and run a meaningful parallel analysis and comparison between GA4 and UA: 

• Users 
• Sessions 
• Pageviews 
• Transactions 
• Channel Reports (Acquisition Channels and Conversion Channels Reports)

The mentioned metrics will allow you to have a comparison between UA and GA4 and enable you to understand the implications for your reporting. 

Make sure to pass the relevant user properties in the configuration tag, i.e. userID or userHash. Passing the userID will allow GA4 to match your users across platforms! 

Long Term Solution

If you have not switched to GTM server-side tagging yet, you will have to make the decision whether to stay with client-side tagging or invest in switching to server-side tagging. Here is a very short Pro and Con list to get you started with making the decision:

Staying with the Client-Side Implementation

Proceeding with the client-side implementation and expanding your short-term solution setup is definitely a viable option and is fairly straightforward. In essence, it means setting up more GA4 events while gradually fading out the Universal Analytics ones. We recommend starting with the most important ones to you. Those are probably the enhanced eCommerce events. Depending on how many third-party tools are additionally integrated on your side it might be more pressing to retire Universal Analytics events to keep the user’s client from slowing down.

Advanced Server-Side Implementation

In case you already have GTM server-side tagging in place or are interested in switching to it, we highly recommend investing in implementing the parallel tracking infrastructure for GA4 there. If you don’t have a server-side infrastructure setup yet, we would recommend to still implement the short-term client-side solution as described above. 

With server-side tagging you can send data from your web container to your server-side container that is hosted on your own subdomain. That way browser protection can be bypassed and the load is taken from your frontend resulting in higher page performance. 

Creating GA4 server-side tags will enable you to utilize the benefits of server-side tagging, while populating the GA4 property. 

Clients who have implemented server-side tagging see an approximately 11% increase in tracked traffic. 

To implement the advanced server-side solution you will need to set up a GTM server-side container. Proceed with sending your Universal Analytics hits via the server-side container to Google Analytics. Then expand this setup.

Additional Things to Consider

Congratulations, you have successfully secured your reporting basis, by building up a GA4 infrastructure. Very likely, there are two more things to consider: 

1. GA4 DataLayer Implementation: With GA4 comes also a new recommended dataLayer structure that should ideally be implemented on your website. Luckily, this is not a prerequisite but rather an optimization step. It is possible to translate the Universal Analytics DataLayer to a GA4 DataLayer by using a custom task in the GTM. In case you have the developer resources it is still recommended to gradually switch to the new GA4 structure as it will improve your site performance.
2. Reporting migration outside of Google Analytics: For many businesses reporting does not stop in Google Analytics. Therefore, plan in enough time to switch your Data Warehouse processes or other reporting tools to the new data structure from GA4.