Why does GA4 count different session numbers than Universal Analytics?

When Google Analytics GA4 counts different sessions than Universal Analytics, it confuses many website owners. GA4 defines sessions differently from its predecessor system. Consequently, a direct comparison of session numbers lacks meaning. In this post about different GA4 session counts, we explain the technical differences. We show you how to properly contextualize the new numbers. Understanding these changes is crucial for accurate data analysis.

Why Does GA4 Count Different Sessions Than Universal Analytics?

In Universal Analytics, a new session started at midnight, with new campaign parameters, and after 30 minutes of inactivity. GA4, however, does not start a new session at midnight or with new campaign parameters. The 30-minute timeout remains the same though. Consequently, this fundamental change in session definition is why Google Analytics GA4 counts different session numbers compared to its predecessor. Specifically, the removal of the midnight reset prevents artificial session breaks.

Furthermore, the absence of new sessions triggered by campaign parameter changes provides a more user-centric view. For example, if a user clicks an ad, browses, then clicks another ad within 30 minutes, UA would count two sessions, but GA4 records one continuous session. This results in GA4 generally counting fewer sessions than Universal Analytics. Additionally, these nuances are vital for interpreting your web traffic accurately. Also check the new bounce rate in GA4, which is also based on sessions. Both metrics are directly connected.

How Big Are the Differences in Practice?

Typically, Google Analytics GA4 counts 10 to 20 percent fewer sessions than Universal Analytics. This range can vary significantly based on your website’s specific traffic patterns and user behavior. For instance, e-commerce sites with frequent user interactions across different marketing channels might see differences at the higher end of this spectrum. Consequently, understanding your audience’s behavior is key to anticipating the magnitude of these changes.

Furthermore, campaigns with many UTM parameters lead to greater discrepancies, as GA4 consolidates these into a single session. This provides a more accurate representation of a user’s journey, even if they interact with multiple campaign touchpoints within a short period. However, GA4 provides more accurate user data by avoiding artificial session splits. The Google documentation on data differences confirms these discrepancies. Consequently, when GA4 counts different session numbers, it often reflects a more realistic engagement pattern.

Our Recommendation

Do not compare GA4 session numbers directly with old UA data. Instead, use GA4 data as your new baseline. GA4 session counts are more accurate since artificial splits at midnight and campaign changes are eliminated. Therefore, only perform historical comparisons within the same system. Furthermore, relying on GA4’s unified approach provides a clearer picture of user engagement over time.

Additionally, we recommend focusing on users and engagement rate rather than sessions alone. Moreover, consider setting up custom events to track specific user interactions that are most valuable to your business. This approach ensures your insights are aligned with GA4’s improved data model. Specifically, when Google Analytics GA4 counts different session numbers, it offers a more robust foundation for future analysis and strategic planning.

Conclusion

GA4 systematically counts fewer sessions than Universal Analytics. The new counting method is more precise and avoids artificial session splits, providing a truer reflection of user engagement. Consequently, businesses can gain deeper insights into user behavior and optimize their strategies more effectively. Therefore, embracing GA4’s session definition is a step towards more accurate analytics.

Our Google Ads agency helps you interpret GA4 reports correctly and leverage these new metrics for better performance. Furthermore, understanding why Google Analytics GA4 counts different session numbers is crucial for making informed business decisions. Additionally, explore other GA4 features to maximize your data analysis capabilities. Also read our post about discrepancies between GA4 and Google Ads numbers.