What is bounce rate?

Two definitions are in use, and they are not the same.

The older one counts single-page visits: someone arrives, views one page and leaves. An online learning site still defines it that way, as single-page visits divided by total visits². Older reports and tools often use this idea.

GA4 turns it around. Google's Analytics Help says a session counts as engaged if it lasts longer than 10 seconds, has a key event, or has 2 or more page or screen views. Engagement rate is the percentage of engaged sessions, and bounce rate is the percentage of sessions that were not engaged¹. Read more at engagement rate.

So a report that just says "bounce rate" can mean two different things. A visitor who reads one page for a minute is a bounce under the old definition and an engaged session in GA4. The two numbers cannot be compared directly. Ask which one you are looking at.

A high bounce rate is not automatically bad. A visitor who reads your delivery page, gets the answer and leaves is a "bounce" in the old sense. They may have been perfectly served.

It is more useful to look at bounce rate by landing page and by traffic source. If one ad sends visitors to a page where most leave without doing anything, that is worth a look. Do not stop at the number. Ask what the page was meant to do.

When you have a theory about a page, an A/B test beats guessing. It splits visitors randomly between two versions. Our ecommerce tracking audit covers the checks that make the numbers usable. To see which numbers GA4 reports and which it does not, read what GA4 counts and what it doesn't.

For ZFD: We care about bounce rate only where it changes a decision, such as which landing page to fix.