What’s the difference between Bounce Rate & Engagement Rate in GA4?

In Universal Analytics, bounce rate was often used as a key engagement metric to assess the performance of landing pages, channels and marketing campaigns.  Whilst available in GA4, the focus has moved to engagement rate.  Why the change and what are the differences between the two statistics?

What is Bounce Rate?

In UA by default bounce rate was the percentage of sessions who had single page interactions with a website. 

If you captured other events on a page, such as users watching a video or downloading a file, then this additional interaction would mean a visitor didn’t bounce (even if they looked at only one page).  It was possible however to set events as ‘non interaction events’ (e.g. for scroll depth) so that additional tracking didn’t adjust the bounce rate. 

One issue with bounce rate was that by default it could sometimes be a bit of a crude statistic.  People performing searches for example might land on a page, spend a fair amount of time on it and then leave - their questions or reasons for the search having been answered.  In the absence of other tracking the user would have bounced even though they may have spent a fair amount of time on the page. 

For this reason many sites set an ‘adjusted bounce rate’ where an event would fire after a period of time had elapsed to signify a level of user engagement with the site and to class the visit as not having bounced.

What’s different in GA4?

In GA4, in part to overcome the issue above, Google have turned bounce rate around into a more positive metric and have essentially implemented a form of adjusted bounce rate.

If users spend over 10 seconds on a page, complete any event you’ve marked as a conversion or view more than one page the visit is marked as an ‘engaged session’. 

Engagement rate is essentially the percentage of engaged sessions your site or traffic segment received.  You can thus use engagement rate in a similar way to bounce rate to assess the performance of landing pages, channels and campaigns.

If you used an adjusted bounce rate in UA, you may want to adjust the settings used for engaged sessions in GA4.  You can do this primarily by adjusting the 10 second timeout event that fires a ‘user_engagement’ event.  To do so log into your GA4 admin interface and then follow the steps below.

Data Collection & Modification -> Data Streams -> Your Website -> Configure Tag Settings -> Show More -> Adjust Session Timeout

Bear in mind that as conversion events also signify engaged sessions, if you use these too broadly (e.g. conversions for popular content) then you may artificially inflate your engagement rate and make it a less helpful metric.

Is engagement rate a more useful metric?

Arguably, engagement rate is a more helpful metric than bounce rate as it helps you understand how many users have had a meaningful interaction with your website.

Have a question on this article or need a Google Analytics consultant to provide help with a project? Why not contact us at info@andersanalytics.com.