Google often makes minor and significant updates and new versions, and this transition from Universal Analytics to Google Analytics 4 is definitely the significant one. Whether you have already set up the Google Analytics 4 or are preparing to set it up, this article will help you see the differences between Universal Analytics and Google Analytics 4.
We have pulled together the key metrics and how they report differently across the two platforms. UA was the norm for a decade before it shut down in 2023, so this was an enormous change, and understanding it is what keeps your reporting trustworthy now that GA4 is the only option.
Now that Universal Analytics is gone for good, the practical next step is a clean GA4 build. Our GA4 setup checklist walks through it, and our GA4 setup service handles the migration end to end.
Side note: The difference between Google Analytics 4 and Universal Analytics filters should be discussed first because we'll refer to it various times in this article. There are two key differences we want to point out for you.
The first key difference is in applying filters. In UA, filters are applied to views. All incoming data comes into the property and will be filtered at the view level when applied to a view. So, you can have one view, which is all-website-data where the data is completely unfiltered and serves as a backup copy and a couple of filtered views tailored to your business needs. In GA4, filtering is done at the property level, so there is no backup given as in UA.
Another key difference concerns the possibility of filtering. For now, in GA4, it is possible to filter only internal and developer traffic, while in UA, we had a much wider range of options. The most important thing to ensure is that you have not filtered data in UA, which cannot be filtered in the same way or at all in GA4.
The short version
- GA4 and Universal Analytics are built on different data models: UA is session-based, GA4 is event-based, so the numbers rarely match one to one.
- The gaps are expected, not bugs: UA reports Total Users while GA4 leads with Active Users, and the two count sessions, conversions and pageviews differently.
- UA counted one conversion per session; GA4 counts every instance of a conversion event, so conversion totals can look higher in GA4.
- Bounce rate is gone, replaced by engagement rate, the share of sessions that lasted over 10 seconds, had a conversion, or saw at least two pages.
- Universal Analytics shut down on July 1, 2023, so GA4 is now the only version, and the practical move is a clean GA4 build.
Users
Universal Analytics (UA) and Google Analytics 4 (GA4) are two very different tools for analyzing website data. After being a standard since 2012, Universal Analytics will leave that role next year. Instead of UA, Google Analytics 4 is taking the lead in the market from 2023.
One of the key differences between these two tools is how they calculate the User metric. UA calculates Total Users, while GA4 calculates both the Total Users and the Active Users but directs only Active Users.
While these terms may seem similar, they represent different metrics. Total Users include all users who have ever visited your website, regardless of whether or not they are currently active. Active Users only include users who have interacted with your website within the given time.
So when your Total Users in UA looks very different from your Active Users in GA4, that is expected, not a bug. What matters is knowing which number you are looking at.
The gap can be confusing at first, but both numbers are useful. Read them as two different lenses on engagement rather than two versions of the same figure.
Pro tip. With the help of Explorations in GA4, you can find your total number of users. These numbers may be more comparable to those reported by UA because they use a different definition for Total Users.
Pageviews
When comparing pageview metrics between Universal Analytics and GA4, it's essential to consider the additional app traffic to compare the two tools accurately. If you're looking at page views, UA will show you a separate count for mobile views, while GA4 will combine web and app views into one total.
Generally speaking, the pageviews should be pretty close, varying by a few percentages, as the global site tag fires on each page and generates a pageview. However, UA and GA4 may provide different data due to your setup filters. Make sure to check our notice about differences in filters at the beginning of the article.
GA4 does not support filters like we're used to with UA. For example, we can filter out internal IP traffic and unwanted referrals with GA4. Still, UA offers additional filters, such as excluding certain geographic regions, that may impact the data contained in the view and cause more significant differences in metrics.
Purchases
Websites rely on accurate data to make informed decisions about how to serve their customers. In particular, purchase events should match closely across user activity (UA) and goal conversion (GA4). Any discrepancies could be misleading and lead to inaccurate business conclusions.
To establish accurate data, you need to be collecting a unique transaction_id in GA4, and UA will ensure you compare similar metrics. The unique transaction_id is merited to avoid sending duplicate data into Google Analytics and distinguish purchases. This will help prevent any noticeable differences in data when comparing UA and GA4. Otherwise, we may draw inaccurate conclusions about customer behavior and purchasing trends.
To ensure that e-commerce data is appropriately collected, pay close attention to the required parameters for GA4 e-commerce implementation. If you notice differences, the cause of the discrepancy between Google Analytics 4 and Universal Analytics might be due to different filters and attribution models.
Pro tip. In UA, the default attribution model is last non-direct click, while in GA4 it is data-driven attribution model. Still, in GA4, every user can choose for themself which one they want to use, and due to that, our suggestion is to put extra time into researching attribution models in Google Analytics 4.
Sessions
The number of sessions varies between UA and GA4 depending on the company and several different factors, including:
1. Geography: pay special attention to this with a global customer base. Consider your users' time zones and how likely they are to cross the midnight threshold, which restarts the session.
2. Using UTMs: it is not a good idea to add UTMs to your own internal links, because they reset the session in Universal Analytics. If you do, UA can report many more sessions than GA4.
3. Using filters: as noted earlier, GA4 does not support all the filters UA had. Look again at the filter note from the start of this article.
Session/Traffic Based Acquisition metrics
Sessions and Users are the center benchmark of differences for acquisition metrics. Since the difference in Sessions and Users in UA and GA4, all session/traffic-based acquisition metrics and reports can also be distinguished. It would help if you first learned about the discrepancy between Users and Sessions to understand in-depth the difference between reports. Therefore, consider the Sessions and Users paragraphs of this article.
Conversions
If you set conversions on destination URLs or UA (i.e., Category/Action/Label), events could be really close between that and equivalent events in GA4 conversion. Despite that, essential differences between UA and GA4 may make a problem for comparison conversion counts.
The bottom line of the difference in UA and GA4 in Conversion metrics is how these analytics platforms calculate conversions. For the same goal, UA calculates one conversion per session. In contrast, GA4 calculates multiple conversions per session for the same conversion event.
Pro tip. You might not always be able to use GA4 conversion events for duplicating some UA goal types literally. It is due to UA's support of five different goal types (destination, duration, pages/session, smart goals, and event goals), while GA4 only supports conversion events. More specifically, you cannot duplicate a smart or duration goal if you use GA4 conversion events.
Bounce Rate vs. Engagement Rate
Earlier, when websites and apps looked different, Bounce Rate was a logical measure of engagement on a site. The user can look at one page on the app and leave without triggering the event, which would be considered a rejection. Now things are different. GA4 uses more logical indicators for our current situation with apps and sites.
Engagement rate is the proportion represented as a percentage of your engaged sessions to your total sessions. It will only count the number of sessions longer than 10 seconds and had a conversion event or had at least two pageviews or screen views. Due to the time threshold of Engagement Rate, which is associated with it, it isn't possible to consider the inverse of Bounce Rate.
Event Count
Events represent the user interactions with the lining on your web page or app. Some of the many events we can measure are link clicks, add-to-cart actions, form submissions, downloads, and time spent on a page to understand user behavior better. The crucial difference in the data model between Universal Analytics and Google Analytics 4 is the events.
The Google Universal Analytics data model is session-based, while the Google Analytics 4 is event-based. Unlike Google Analytics 4, Universal Analytics data is sent as pageview hits and event hits, with some primary e-commerce data sent as transaction hits.
Each event in GA4 is noted with the event_name parameter, with additional event parameters to describe the event. In UA, you must look for the built-in Event Category/Action/Label taxonomy and memorize indexes for custom metrics and dimensions. In GA4, the event parameters will start with event_name, and you include other parameters to specify the interaction. The maximum number of parameters is 25, through which we sent all the information. Thanks to this change, we have more options for sending data than there were in UA. The event-based data model contributes that each parameter can serve a more specific and meaningful role.
Events are defined as any user interaction on a site (page views, transactions, social interactions, etc.). Moving the focus from sessions to events benefits marketers, such as cross-platform analysis and an enhanced capacity for pathing research.
These events are automatically logged to your App or Web page. Enhanced Measurement GA4 has made everyday tracking like scrolls, outbound clicks and file downloads available out-of-the-box with little to no configuration required. Events can collect and send pieces of information that specify the action the user took or add further context to the event or user. This information includes the value of purchase, the title of the page, or the user's geographic location.
Pro tip 1. Check 4 different types of events in which GA4 differs:
- Automatically collected events.
- Enhanced Measurement events.
- Recommended events.
- Custom events.
Pro tip 2. You should pay attention to character limitations while making events:
- event_name: maximum 40 characters;
- event_parameter_name: maximum 40 characters;
- parameter value: maximum 100 characters.
Pro tip 3. GA4 lets you create and modify existing events right in the interface, which is worth getting familiar with. You will find it under Configure > Events.
Final Thoughts
Universal Analytics shut down on July 1, 2023, and Google Analytics 4 is now the only version Google runs. If your GA4 is not in good shape yet, that is the place to start; if it is, the next step is learning to read it well.
If you are setting GA4 up from scratch, our GA4 setup checklist walks through it, and our guide to GA4's benefits covers what is new. If you would rather hand the measurement to a team that lives in it, that is what our web analytics service is for.
Frequently asked questions
What is the main difference between UA and GA4? The data model. Universal Analytics is session-based, while GA4 is event-based, where every interaction is an event with its own parameters. That single change is why so many metrics report differently across the two.
Why do my UA and GA4 numbers not match? Because they define metrics differently and filter data differently. UA reports Total Users where GA4 leads with Active Users, they count sessions and conversions on different rules, and GA4 cannot apply many of the filters UA could. Different attribution models widen the gap.
How do conversions differ between UA and GA4? UA counted one conversion per session for a given goal, while GA4 counts every instance of the conversion event in a session. UA also supported five goal types, where GA4 has only conversion events, so some UA goals cannot be copied across exactly.
What replaced bounce rate in GA4? Engagement rate. It is the share of sessions that lasted longer than 10 seconds, had a conversion event, or included at least two page or screen views. Because of that time threshold, it is not the inverse of the old bounce rate.
Is Universal Analytics still available? No. Universal Analytics shut down on July 1, 2023, and GA4 is the only version Google runs now. If your GA4 is not in good shape yet, a clean setup is the place to start.
