A new approach to calculating user session in GA4

January 24, 2023

Kayla Shampine
Google Analytics 4 offers many new opportunities for marketers, including a more accurate approach to measuring user sessions. Learn more about this new approach to measuring this data point.

A new approach to calculating user session in GA4

A user comes onto your website, tinkers around for a bit, and then leaves. How long did they stay? How often, if at all, did they view your website again? All of these questions can be answered with data from a website analytics platform like Google Analytics. This collection of data has allowed marketers to optimize their websites to align with their users’ needs. A key data point? User sessions. While user sessions are nothing new in the marketing landscape, Google Analytics 4 (GA4), Google’s newest analytics platform, has altered the way these data are both collected and calculated to improve their accuracy. What does this mean for marketers? Spoiler alert: more accurate data for marketers to optimize against than ever before.


How user sessions are calculated in UA

Before GA4, Google’s Universal Google Analytics (UA) was its primary analytics platform. Within UA, user sessions begin when a user accesses a website and begins browsing for information and expires when there is either 30 minutes of inactivity or at midnight in the UA property view’s time zone. However, this approach can be problematic as users are not always in the same time zone as brands. For example, a brand’s view may be set up in Eastern Time, yet a user may be on the brand’s website and reviewing the content in Central Time. While it might not be midnight for the user, if the view’s time zone strikes midnight, the user’s session is ended and a new one is started. 

In addition to time-based session expiration, UA utilizes campaign-based session expiration. This means if a user picked up new campaign parameters during their current session, that session would expire and a new session would begin. This situation may sound rare, but in the age of multitasking, it’s not incredibly unusual. Consider a user who’s browsing the internet in multiple tabs: they may click on a paid search ad for a brand’s site in tab one and start a session — perfect! They then switch over to tab two to check social media and encounter a display ad for the brand’s site. Charmed by the ad, they click through to the site again. But, since this results in a change in campaign parameters, UA ends the session in tab one and starts a new session in tab two. This creates an inaccurate measure of visitors to the site because some sessions may be the same person viewing the content in a different tab. With consumers viewing content from multiple platforms, these instances could skew an important data point for marketers to optimize against.

Both time-based and campaign-based session expiration have led to an excess of user sessions and inaccurate data for marketers to optimize their website against. Enter GA4.

How user sessions are calculated in GA4

GA4 eliminates these issues with an enhanced approach to measuring user sessions. A user’s session still expires when there has been 30 minutes of inactivity, but time zones are no longer an issue — sessions can last indefinitely as long as the user continues to trigger events on the website. Sessions are also not restarted when new campaign parameters are encountered. For example, if a new campaign value is found in the middle of an existing session, that value would be associated with the corresponding event. However, the new campaign values are not associated with the source of the session. This provides a better, more accurate collection of a website’s user sessions. 

How can marketers make their user sessions even more accurate with GA4? 

While GA4 has removed key issues in user session data collection, marketers can still take additional steps to elevate these data. How? By considering consumer behavior when building their approach to measurement.

As stated before, a user session in GA4 automatically expires after 30 minutes of inactivity — but this might not be the most effective way to signal that the session has timed out. This is especially true for sites in industries where users conduct a significant amount of research prior to converting (think buying a car or booking a flight), sites with a high volume of reference content or tutorials (think Wikipedia or Wikihow), or if it is typical for the user to engage with content in the background (think streaming media). GA4 offers the option to extend a website’s session expiration up to nearly eight hours. By extending to one-to-four hours, this would give an even more accurate viewpoint of these data that can create actionable steps for marketers.

User sessions are an important data point when analyzing website performance. With GA4, sessions can be calculated even more accurately than ever before.

GA4 has been able to evolve the collection of user session data to better align with how users are leveraging website content. And while there are additional steps marketers can take to ensure their data are more accurate, our experts do not recommend marketers draw conclusions from using site sessions as the sole metric. Why? Combining site sessions with new and returning user count, average pageviews per session, and average site session duration metrics provides a better understanding of a website’s quality of growth. 

To let the site sessions metric truly shine, compare this data point to GA4 goals and conversions; it’s worth doing some troubleshooting of the user experience in the conversion funnel if your site sessions are seeing significant growth but your goals aren’t matching pace. 

While GA4 is an important data platform for marketers to collect and manage their information, brands must ensure theirs are set up for success. If you are looking for a partner to implement and streamline your GA4 practices before it becomes the standard analytics platform in July 2023, please connect with us and our experts would be happy to assist.