Understanding Google Analytics’ Average Time on Page
Do you ever wonder how much time people spend reading your content? If users only spend two minutes on a page, but the content should take about ten minutes to read, this information can help signal that it’s time to change things up and make your content more engaging.
The Google Analytics “average time on page” metric helps you understand which pages your users spend time interacting with, and which pages aren’t performing well. But before diving into average time on page, it’s important to understand the definition of average session duration.
What Is Average Session Duration?
Here’s how to calculate average session duration:
Total duration of all sessions (in seconds) / The number of sessions
Individual session duration is calculated differently depending on whether or not there are interactions, also known as engagement hits, on the last page of a session. An engagement hit is counted when a user enters a page and interacts with it in a specific way that you’ve set your Google Analytics to track.
For example, a page is often set to track playing a video as an engagement hit. If, on the final page you visit in a session, you:
- Hit play on the video, the session duration is tracked up until the moment you hit play.
- Don’t watch the video, the time spent on that page is not counted in the total session duration.
What Is Google Analytics’ “Average Time on Page” Metric?
Average time on page is simply the average amount of time all users spend on a single page. But measuring it isn’t as straightforward as you’d think. Here’s why:
- Google Analytics tracks time on page and time on site by measuring the difference between the timestamps of hits. If the visit is a bounce (that is, the visitor leaves after viewing just one page), no time will be recorded.
- Google Analytics keeps counting your time on a page regardless of whether the browser window is in a hidden or visible tab.
- Ex: you probably have more than one tab open right now. Each tab is still tracking time spent on that page, even though you technically aren’t viewing the page.
The result is that “time on page” is an average taken from only the non-bounces for a page, which is a smaller sample size than actual hits for a page. That being said, for a basic Google Analytics account with no custom events set up, you can assume the following two facts.
Fact 1: Google can’t measure the time a user spent on the last page of their visit to your site.
If you haven’t read our explanation of sessions yet, it may be a great primer for the rest of the explanation here. If a user exits your site by closing the window, closing the tab, or typing another website into the URL bar, Google Analytics can’t track this. This means that the metric is often inaccurate for websites such as blogs, where users tend to leave right after they get the information they’re looking for.
Fact 2: Average Time on Page > Average Session Duration (most of the time)
This is caused by two factors of the metric calculations:
- The Google Analytics average time on page metric only takes into account the non-exits and non-bounces. Most sites have bounce rates higher than 50%, and the average time on page is taken from the other half of users who don’t bounce.
- Average Session Duration counts all bounces as zero seconds. This means the higher the bounce rate and exit rate, the lower your average session duration will be.
The end result is that neither average session duration nor average time on page are statistically significant representations of the real time a user spends on your site. So, we always recommend setting up custom event tracking for more accurate tracking and insights into user behaviour.
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