Bounce rate: what it measures in GA4, and when to worry about it

The Google Analytics 4 definition

“Taux de rebond”, the French for bounce rate, is searched 1,600 times a month in France. In GA4, both metrics rest on the same idea, the engaged session. Google defines it as a session that meets at least one of these conditions:

• it lasts longer than 10 seconds;
• it includes a key event (a quote request, a purchase, a click on the phone number, if you have marked them as such);
• it shows at least 2 pages or screens.

Engagement rate is the share of engaged sessions; bounce rate is the share of the rest. Google’s example: a visitor reads for less than 10 seconds, triggers no event and views no other page. If they were the site’s only visitor, the engagement rate would be 0% and the bounce rate 100%.

Google specifies that the first_visit, first_open and session_start events do not count towards engagement, even when marked as key events.

Why your old bounce rate is not comparable

The old definition, from Google’s historical help page on bounce rate, was blunter: a bounce was a single-page session that sent only one request to Analytics. A visitor who read an article for five minutes and then left counted as a bounce.

In GA4, that same visitor is an engaged session, because they stayed beyond 10 seconds. The two figures therefore do not measure the same thing: do not compare today’s bounce rate with one from an old report, and be wary of “averages” that mix both definitions.

What is a good bounce rate?

There is no universal good bounce rate, and we will not give you one: the ranges in circulation generally cite neither their source, nor their definition, nor their sample. Google’s old help page already said so: a high bounce rate is only a problem if the visitor needs to see more than one page for the site to do its job.

Judge each page on what it has to do:

• A home page or category page should lead elsewhere: a high bounce rate there signals a real problem.
• An advice article can answer the question completely: in GA4, reading for more than 10 seconds already counts as engagement.
• A contact or service page where the visitor calls: if the click on the number is not measured as a key event, the call can look like a bounce. Measure it.
• A sales page: the only figure that matters is the share of visitors who buy or ask for a quote.

The right comparison is internal: the same page from one month to the next, or the same page by visitor source (Google, ads, social media).

Showing bounce rate in GA4

By default, most GA4 reports show neither engagement rate nor bounce rate. Google explains how to add them, provided you have the Editor or Administrator role:

1. 1
   Open a detail report, for example “Pages and screens” (“Overview” reports do not let you add a metric).
2. 2
   Click “Customize report”, then “Metrics”.
3. 3
   Add “Engagement rate” and “Bounce rate”, then apply.
4. 4
   Save the change to the report: the two columns appear on the right of the table.

Lowering the bounce rate of a page

Google sets out the method: check whether the problem affects the whole site or only certain pages or sources, then, for a given page, check that its content matches what brought the visitor there and that it makes the next step easy. In practice:

1. 1
   The page answers the search or the ad that brought the visitor: same promise, same words, from the title onwards.
2. 2
   The answer or the offer in the first sentence, with no introduction.
3. 3
   An action visible without scrolling on mobile: a button, a tappable number, a short form.
4. 4
   A page that loads fast: Google sets a good experience at an LCP of 2.5 s or less.
5. 5
   Links to the logical next step: the related service, the guide that answers the next question.

Measuring right: the events that change everything

A bounce rate is only reliable if the important actions are measured. If the page is widely read but nothing is measured, or if the tag is missing on some pages, the figure is wrong. Google recommends checking that every page carries the measurement tag.

• Mark what has value as key events: form submission, click on the phone number or WhatsApp, purchase, guide download.
• GA4 enhanced measurement records a scroll event the first time the visitor reaches 90% of the page height: a good reading signal.
• For a shop, the ecommerce events (add to cart, begin checkout, purchase) show far better than a bounce rate where the visitor drops off.
• In Europe, GA4 only sees visitors who accept measurement: the figures are a sample, not a total.