Average session duration in Google Analytics

I often get asked about average session duration in training sessions. And I often see it given a lot of energy and attention in KPIs and dashboards for reporting site performance.  This post shows how we approach this metric.

Conversions & conversion rates are paramount

I mention this a lot when talking about any other metric other than conversions or conversion rates.

The number of conversions your site/app is generating, and the rate at which your site/app is generating them (conversion rate)… beats average session duration.  If your average session duration increases, but your conversions or conversion rate decrease… then it’s a bad thing, and bad for the performance of your site/app.

What is the duration of a session

The time it takes from the first hit sent to analytics in a session (typically a pageview), to the last hit to be sent.  All within the expiration date for the session, which as default is 30 minutes.

E.g. the below session = 5 minutes long:

Total amount of time / total number of sessions = average session duration in a given date range

Last piece of hit data

Remember, the session is only as long as Google Analytics can record hit data.  In the below example, this session duration is still only 5 minutes, as the user didn’t do anything on that final page.  I.e. they didn’t send any hit data (page / event / custom hit) into Google Analytics on that final page:

Average session duration ambiguity

Is a higher average session duration a good thing?  We’ve seen average session durations decrease when conversions & conversion rates have increased.

A higher average session duration could mean higher engagement

A higher average session duration could mean that users are taking longer to find content, and complete the tasks.  It could indicate higher user frustration.

Like any metric, it needs to be analysed in context.  And it needs to be analysed alongside conversion rates.

How we analyse session duration

We like to get a feel for how the metric relates to conversion rates.  To see if there is a conversion rate ‘sweet spot’ for a session duration range:

We also like to look for session duration ‘sweet spots’ in context.  I.e. by journey: