Google Analytics, Google Analytics 101, Marketing

Google Analytics 101: What Are Sessions?

By Jon Elordi

I am starting a new series on the basics of Google Analytics, called Google Analytics 101. This first post will be on one of the more important and somewhat confusing concepts in Google Analytics: Sessions. If you want to see quick definitions of Google Analytics Terms, might I suggest my Google Analytics Glossary.

Where Are Sessions Used?

Sessions are the bedrock traffic metrics in Google Analytics. Every traffic report has sessions as its main metrics. The audience reports, the acquisition reports, and most of the behavior reports use sessions. Goals and conversions also have the option to use sessions if you set up destination goals.

The behavior reports based on pages are the only reports to not utilize the session metric. Their main metric is pageviews. But that’s only some. The Landing ages report uses sessions as its main metric. More on that in another post.

So it’s safe to say Google Analytics is overrun with the use of sessions.

What Are Google Analytics Sessions?

The formal definition, “Sessions are a group of user interactions with your website that take place within a given time frame.” That’s straight from Google’s mouth. And not overly helpful if you’re new to working with the platform.

The informal definition, “It’s a visit to your the website.” That’s straight from my mouth. It is just a website visit. In fact, it is a bit of a pet peeve of mine that Google did not go with a more intuitive naming convention. The three main traffic metrics are Sessions, Users, and New Users. And it could have been so much simpler. It could have been Visits, Visitors, New Visitors.

The Formal Definition

Let’s break down the formal definition. While understanding sessions as visitors is intuitive, it lacks nuance. Understanding the formal definition of sessions will be helpful as you advance.

Groups of user interactions with your website

There are various ways to interact with a website. The two most popular are pageviews and events. For example, say you go to a website. Click through a few pages, and then watch a video. This would be several pageviews and several events. This is what Google means by a “group of user interactions.” All of these interactions would be part of ONE session.

This of it as visiting Disney World. You go to the theme park. Ride a few rides, eat at the food court, and buy a stuffed Mickie Mouse. These are all interactions you had at the park, and are all grouped in under your Disney World session.

All actions taken within a continuous visit on your website are grouped within a session.

How Do Sessions End?

Session has various ways of ending. The obvious way to end the session is to leave the site. Once the user is off the site, they are no longer having interactions, and there is nothing more to record.

The other main way to end a session is through time. After 30 minutes of inactivity, a session will end. After every interaction with the website the session expiration timer resets. It is possible to adjust the timer to be higher or lower than 30 minutes. If that’s something you’re interested in doing, here’s the Google documentation on how to do that. That adjusting the default session time is rare.

For example, you were on a site and left it up while you went to work out. You come back 45 minutes later and resume what you were doing on the site. This would be two sessions. The first session started before you when to work out, and expired while you were away. A new session started when you returned and began interacting with the website again.

If however, you had only been gone for 15 minutes. That would all have been one session. As the 30-minute session expiration would not have been reached.

A lesser-known way for sessions to end is at midnight. Sessions automatically reset at midnight. If you start browsing a website at 11:55 PM and are still on it at 12:03 AM. You’ve created two sessions.

I’ll be honest. I have no idea why Google has it set up this way. I’ve never had any issues with it. But it does have the potential to cause issues.

Google Analytics Sessions Are Just Visits

In the end, I still think the most useful way to think of sessions is as website visits. It’s important to know exactly how sessions are calculated and to know who they’re different from User(that’ll be a different post). There will come a time where the data will look odd and it will be because of the formal definitions. But those times are not the norm. For most of what you’ll do in Google Analytics understanding them as the visit count is the most intuitive.