A person stands in front of a chalkboard filled with equations and math formulas.

Comparing Metrics for UA and GA4: What Differences to Expect

Cade Egbert
Senior Analytics Associate
May 7, 2023

Leveling Up Is Awesome…

We’ve all transitioned from one education level to the next—middle school to high school, high school to college, undergrad to grad school. While these changes are generally exciting—so many new opportunities!—they’re also stressful.

This is because at each new level, even though the goal of education remains the same (to learn), expectations, teaching techniques, and study methods all change dramatically. Thus, leveling up in education imposes a learning curve independent of acquiring deeper subject expertise.

But There’s a Learning Curve

This is the same learning curve you may be experiencing if you’ve recently migrated your Universal Analytics account to a Google Analytics 4 property. You’re deepening your expertise in measuring traffic for your website or app to make informed business decisions, and since GA4 is a level up from UA, you’re grappling with new expectations and methods.

Since features have changed between the two platforms, measurement has changed, too. This post is for users who want to understand the similarities and differences between UA and GA4 data sets to ensure new implementation accuracy. It explains how GA4 levels up your knowledge by measuring differently from UA and clarifies how (or whether) to compare metrics between the two interfaces.

If you have yet to make the switch and are unsure how to do it, it’s the perfect time to take our free assessment and get individualized considerations and a step-by-step guide to help you plan and execute your transition to GA4.Remember (at the time of writing this article), Google has said that on July 1st, 2023, all Universal Analytics accounts will stop processing data.

Data Model Changes between UA and GA4

Universal Analytics tracking is based on sessions and pageviews, so it’s straightforward to calculate metrics such as bounce rate, total users, or sessions per user. The collection process is different in GA4. Since the model centralizes on events instead of pageviews and sessions, we can not compare exact apples-to-apples with our two data sets.

Forgive us, but if we were to make the two platforms apples, the flavors of UA and GA4 would be as different as Red Delicious from Honeycrisp: Different. Leveled up. We’ve made the table below, based on Google’s definitions, for a quick view of high-level metrics and how they are measured differently in each respective interface.

Screenshot 2023 05 12 at 22.06.00

User Definition Changes and Upgrades in GA4

Within the reporting instances, comparing Users (UA) to Total Users (GA4) seems like a basic one-to-one comparison. But, again, they are not because of the different data models. Additionally, a new metric in GA4, Active Users, measures users not just by those who have triggered an event but by those who have an engaged session with any of the first visit events.

Additionally, you may experience differences in measuring your total users due to filters set in your UA property or if you expect an equivalent comparison between Client ID in UA and User ID in GA4. These instances could contribute to different user counts between your reporting identities. Despite the varying counts, Google is still measuring your overall user instances—just in different ways.

Screenshot 2023 05 15 at 22.23.49

Session Discrepancy Scenarios

Sessions in Google Analytics 4 are counted by the overall session_start event. While the overall sessions are generally measured the same as in Universal Analytics, there are differences. For example, in GA4, sessions are not restarted at midnight, and new sessions aren’t counted when new campaign parameters are set. Because of these differences, your use of UTMs on your site, data filters, and geography (when midnight is hit), are all instances that could cause discrepancies when comparing sessions within UA and GA4.

Above is an example of total Session and User counts differing from the respective platforms. This data was pulled from the same seven-day date range. While there is no hard, fast rule for deltas in your data, anything over 20% should be investigated.

Pageview Caveats

Per Google, “Universal Analytics measures screen views in separate mobile-specific properties, whereas GA4 combines both web and app data in the same property. If you are tracking both web and app data in your GA4 property, be sure to take the additional app traffic into consideration when comparing pageview metrics between the two.” That’s the story there, but also note that while Views between the two platforms are similar, Unique Pageview is a metric that’s been deprecated in GA4.

Goals & Conversions

You can align your goals within Universal Analytics to your Google Analytics 4 conversions. However, it is important to create events in GA4 that are specifically designed to fire when the goal did. For example, if you have a goal based on visiting certain pages, you can create an event to specifically target when a page view event fires on a particular page. Then you can mark this as a conversion event in GA4.

Universal Analytics only counted one conversion per session per goal, whereas GA4 should (usually) count every time your conversion event is triggered. You must take the time to make sure that each goal has been created as a separate event during your implementation phase, in order to be able to compare the goals and conversions, however similar they may be.

Bounce Rate

In Universal Analytics, bounce rate is calculated by using the percentage of sessions where single page interactions had no interaction. In Google Analytics 4, it is calculated by the percentage of sessions that were simply not engaged sessions, which is the inverse measurement of the newly-created engagement rate. Because these metrics are calculated differently, they should not be compared one-to-one.

Total Events & Event Count

Due to the depreciation of Event Category, Event Action, and Event Label, major event differences exist between the two platforms.

Total Events in UA was calculated by each instance of a Category, Action, or Label firing. It wasn’t always a reliable metric because a singular user action could have all three events. By contrast, in GA4, the Event Count metric is calculated by every event defined in tag manager or through enhanced measurement events.

Comparing Total Events and Event Count does not encapsulate the actions that users are taking on your site/application, and these two metrics aren’t one-to-one.

The World is Your Oyster, GA4 Graduate

If you’ve been using Universal analytics for quite some time, you may have grown accustomed to measuring your website or application in a certain way. Google Analytics 4 introduces so many new concepts and measurement strategies that comparing the two platforms may cause frustration. This is normal.

Know that the new measurements aren’t one-to-one with the old ones because the way we collect and identify useful data has changed. The platform has graduated—and you can, too—to encompass measurements to help you make the best business decisions for this new data reality. The data set is different, but the objective remains the same—just a level up.

Search Discovery is a trusted Google Partner

Search Discovery is a Google Premier Partner and has been a certified Google Analytics 360 sales partner since 2012. This means we can offer competitive pricing for GA4 360. For both the paid and free versions, we can help you transfer your historical data as you implement, perform tagging updates, train your teams, and integrate your media platforms. We started migrating clients to GA4 during the beta program in 2019, and we make the process quick and efficient for you.

Additionally, we have created in depth training videos and quizzes to help guide you on your GA4 journey. Please reach out if you are interested!

Speak to a Google expert to better understand the transition to GA4!

Cade Egbert
Senior Analytics Associate

Read More Insights From Our Team

View All

Take your company further. Unlock the power of data-driven decisions.

Go Further Today