Google Analytics 4 Bounce Rate
The Google Analytics 4 Bounce Rate is the percentage of non-Engaged Sessions.
Google Analytics 4 has recently introduced Bounce Rate, a well known metric in Google Analytics 3 (GA-UA). Note: GA4 Bounce Rate cannot be compared with GA-UA Bounce Rate as they are not derived in the same way.
A bounced session is defined in GA4 as a non-engaged session - so it is effectively the inverse of the GA4 Engagement Rate. If your Engagement Rate is 58.43% then your Bounce Rate is 41.57%. Engagement Rate and Bounce Rate always adds up to 100% - the one you use will depend on whether you are a “glass half full” or “glass half empty” sort of person!
The GA4 Engagement Rate is the percentage of Engaged Sessions - the higher the percentage the better (as opposed to the GA-UA bounce rate where a lower percentage was preferable).
An engaged session is one that meets any of these 3 requirements
Stayed on the page with the window active for 10 or more seconds (10 seconds is the default - within GA4 admin you can adjust the threshold to 20, 30, 40, 50 or 60 seconds) OR
Visited 2 or more pages OR
Triggered a conversion event.