What are we talking about?

Before we start to unpack what is going on in the Analytics world and why so many people are so nervous, you need to clarify concepts. To do so, we’re going to give a brief definition of each of the players involved to make it clear who’s who in all of this.

Google Analytics (GA) / Universal Analytics (UA)

Google Analytics is an essential tool for exhaustive monitoring of our website, although it can also be used for social networks and blogs. It is the tool that offers us the most metrics and with data as important as the total number of visits, the duration of each one, the total number of conversions, which have been the most visited pages or what have been the sources of this traffic.

Making use of cookies, browsers and JavaScript, it also gives us clues as to which sections have been the users’ favourites, the keywords used and the device, browser and operating system used by our audience.

And before we forget, besides being the most complete and used, Google Analytics is free.

Here´s the drawback. Google has already announced that it is not going to make any more updates to Universal Analytic because it is going to dedicate itself fully to Google Analytics 4. So it seems that UA’s expiry date will be 2023. So it’s time to renew or die. And it would be very sad to die for not renewing.

Google Analytics 4 (GA4):

Although there is now more shouting and despair in the air, all this is nothing new. In 2019, Google Analytics was Web+App and now, in order to avoid any confusion, it has been renamed Google Analytics 4 or GA4. So you might say, what’s new, old friend?    

In a nutshell, GA4 is a giant update that will eventually overtake the original. If you already have a UA account, we recommend that you get started on GA4 because that will be the future, and the present. If you don’t have an account yet and want to introduce it to your business, then go straight to GA4.

Differences between Google Analytics (Universal) vs GA4 (Google Analytics 4)

The main difference is that UA is based on the observation of pages and sessions while GA4 is based on events and parameters. That is, any type of action that is going to take place on our website.

The first naming of GA4 as Web+App could not be clearer. Its goal is to unify all data collected from your website, Android and iOS apps under one property and deliver it in one report.

The unfiltered data view in terms of data flows will no longer be possible in GA4. Filters will be applied at property level.

In GA4 it will be easier to create custom Ad Hoc reports that are tailored to different functions using Explorations. In addition, you can use templates that are divided by techniques, use cases and sectors, and include all types of reports.

In UA, conversions are measured as e-commerce transactions or as goals. GA4 simplifies it by categorising conversions as any event that brings value to business goals.

Differences in metrics


UA has two user metrics; total and new users. In GA4, there are three user metrics; Total, Active and New. 

UA reports Total Users as Users while GA4 focuses on Active Users, which it shows as Users. So, although we talk about Users in both cases, the metric calculation is different; UA uses Total Users and GA4 uses Active Users.

Page views

The differences may vary depending on the filters you have set up in Universal Analytics or Google Analytics 4. 

UA tracks screen views in mobile-specific properties with the option of additional filtering that can affect the data, whereas GA4 combines web and application data together and does not support filtering.


The session duration in GA4 is calculated based on the time interval between the first event and the last event of the session. Whereas in UA it has defined parameters for what can cause it to end, e.g. a session will end after 30 minutes of inactivity and a new session will start at midnight or after a timeout with no activity.

The difference in session counts between UA and GA4 may vary depending on factors such as geography, use of UTMs, filters applicable in UA or use of estimation. Google Analytics 4 uses a statistical estimate of the number of sessions that have occurred on the website or app through the number of unique session IDs.

Session/traffic-based acquisition metrics

If we move by UA this metric is found in the Acquisition section in a number of different reports, such as the Channels report or the Source/Media report. The Channel or Source/Medium is the dimension that is analysed with respect to metrics such as Users and Sessions.

Whereas in GA4 the traffic acquisition metrics are found in the Traffic Acquisition report, logical right? The Channel or Source/Media dimensions are measured with metrics such as Users and Sessions.


Whether based on destination URLs or events (i.e. Category/Action/Tag) for conversions can be quite similar between the two tools, albeit with nuances.

UA counts only one conversion per session for each target. That is, if a customer submits a form twice during the same session, it will count as only one. While GA4 counts each user action in its session. This means that in the above situation, both submissions will be counted.

Universal Analytics supports five types of goals: destination, duration, pages/session, smart goals and event goals. GA4, on the other hand, only supports conversion events.

Event counting

Events represent a fundamental difference in the data model between the Universal Analytics and Google Analytics 4 properties.

If the website we are working with has a registration form and a single button where the sign_up event would be triggered, with both tools the count will be quite similar. The change comes if we have multiple signup events, the comparison of the event count between GA4 and UA can vary a lot and not be straightforward as the GA4 reports do not show the Category, Action and Tag.

To sum up

We can highlight that the strengths of this GA4 are the ability to measure both the degree of engagement with users and the results of personalised events in a simple and effective way. Without forgetting its main mission of unifying metrics, whether from a website, app or social network.

In addition to having a powerful debugging tool to measure what previously could not be measured in conversions, it exports the data obtained in Big Query.

GA4 creates a unified view of the user’s journey through the website or app and adds greater flexibility to reporting.