By default, when will google analytics not be able to identify multiple sessions from the same user?

Last Updated: May 20, 2022

Understanding users in Google Analytics

In Google Analytics,  a user is a person who has visited your website. If the person has visited your website for the first time, they would be counted as a ‘new user’, and if a person has visited your website more than once, they would be counted as a ‘returning user’. Let’s understand it more technically.

For Google Analytics, a user is a combination of a unique random number and the first timestamp. This combination is called ‘Client ID‘.

When a user visits your website for the first time, this Client ID is generated by the Google Analytics script and placed in a cookie value in your browser’s local storage data.

When someone visits your website, Google Analytics checks for the Client ID. If the Client ID is present, Google Analytics considers them a returning user and starts a new session. If the Client ID is not present, Google Analytics will consider them a new user and generates a new client ID.

Thus, the Client ID comprises a unique random number and the first timestamp. The first timestamp is the time of the first visit by a user or the time when the Google Analytics cookie was first set for the user.

Following is an example of a Client ID: 124562358.46738999

Here, ‘124562358’ is a unique random number, and ‘46738999’ is the first timestamp.

Client ID is assigned to each unique user of your website/app.

The Client ID is set by the _ga cookie (the Universal Analytics Cookie).

Below are some of the scenarios where Google will not be able to identify the same users as returning users. Let us take an example to understand this better.

Scenario-1: A user visits your website for the first time from a personal laptop, and Google Analytics assigns it a Client ID since it is the first visit and they are considered a new user.

Scenario-2: The same user now uses his mobile device to access your website. Since Client ID is not present, Google considers them a new user. However, he is the same user who accessed your website from a personal laptop earlier.

Scenario-3: If the user clears his cache and cookies, the Client ID will be deleted, and a new Client ID will be generated. Although the same user is accessing our website, Google still considers this user a new user since the Client ID was deleted.

Google uses two methods for calculating users. 

#1 Precalculated method: This method calculates users for a single dimension like date of the year, week of the year, or month of the year. This calculation method is used for smaller date ranges where data is retrieved from the already existing tables and serves the reporting needs quickly. This is used for audience overview reports or to build a custom report without adding any segments.

#2 Calculated on the fly: This method is used on much larger data sets. It takes longer than the precalculated method as it has to retrieve the data from the raw and unprocessed tables. Reports generated using this method may undergo sampling if certain conditions are met. However, Google Analytics 360 users can request unsampled reports.

The following steps will guide you in checking Client ID on your website:

How to check Client ID (aka _ga cookie in browser)

Step-1: Click on the three dots in the left corner of your Chrome browser and then click on ‘Settings’.

Step-2: Scroll down and click on ‘Cookies and other site data’ in the ‘Privacy and security’ section.

Step-3: Scroll down and click on ‘See all cookies and site data.’

Step-4: Look for your website domain and click on it

Step-5: Click on “_ga”, and in content, you will find your Client ID

_ga cookie is made up of the following four fields:

Another simple method to check Client ID in the browser:

Step-1: Load the URL in the browser for which you want to check the Client ID. Let’s load www.optimizesmart.com in the browser.

Step-2: Now, open the developer console by following the command (ctrl+shift+I).

Step-3: Navigate to the ‘Application’ tab.

Step-4: On the left-hand side, click on cookies and then on https:www.optimizesmart.com, as shown below.

Step-5: On the right-hand side, you will see all the cookies set for this site.

Step-6: Check for_ga cookie, which is our client ID.

This is what a user looks like to Google Analytics.

The first field is the version number like GA1.

The second field is the number of components at the domain level, separated by a dot.

By default, the _ga cookie is set on the top-level domain with the root level (/) path. So if you have set a cookie at the top-level domain like optimizesmart.com, then the second field would have a value of 2 as there are two components separated by a dot. One component is ‘optimizesmart’, and the second component is ‘com’.

If you have set up a cookie at the sub-domain level, like analytics.optimizesmart.com, then the second field would have a value of 3 as there are now three components separated by a dot. The first component is ‘analytics’. The second component is ‘optimizesmart’. The third component is ‘com’.

The third field is a random unique ID (randomly generated number). Here 908899769 is the unique random id.

The fourth field is the first timestamp, i.e. the time when the cookie was first set for the user. Here 1600020018 is the first timestamp.

The third and fourth fields together make the client ID. So the client ID would be 908899769.160020018. 

You can retrieve client ID through the ‘ga.getAll‘ method:

var clientId = ga.getAll()[0].get(‘clientId’);

and then send it to Google Analytics by creating a new custom dimension (with session scope):

 ga(‘set’, ‘dimension1’,clientId);

By default, the Client ID cookie expiration time is two years. For example, if you visit today and do not visit the site for two years, your cookie will expire, and a new cookie will be generated.

Let’s say you have visited the website today, and Google Analytics assigns a Client ID to you, and the Client ID expiration time is set to two years. However, if you go to the same site from the same browser within two years, then Google analytics will understand that you are the same user, and cookie expiration will be set to expire two years from the time of your visit. 

Let’s make it simple; if you visit the site daily, your Client ID will not expire unless you delete your cookies.

How Google Analytics counts new and returning users

The first time a device (desktop, laptop, smartphone, etc.) or a browser (like Chrome, Internet Explorer) loads your website content, the Google Analytics tracking code creates a random, unique id called the client ID and sends it to GA server.

This unique id is counted as a new unique user in GA. Every time a new id is detected, GA counts a new user.

When GA detects an existing client ID in a new session, it counts it as a returning user.

If the user deletes the browser cookies, the ID gets deleted and reset to a new client ID on their next visit to the website.

If the user switches device or browser on a return visit to your website, a new unique client ID is created, and the returning user is counted as a new user, as the client ID exists only on the device/browser where it has been set.

That’s why the client ID cannot be used to measure across devices.

The new user metric allows you to identify how many people visited your website for the first time. These metrics can be helpful in understanding how your marketing campaigns are performing and whether they are able to drive new users to the site.

Returning users metric helps us understand how many people came back to your site after their first visit. For a publication or blog, it is expected that we should see a large number of returning users, which will help businesses understand that users are consuming the content published on the website.

Google Analytics does not report on unique users

Google Analytics does not report on unique users anymore.

If you go to Audience > Overview report, you can see a report like the one below:

According to Google’s own definition:

The ‘users’ metric includes both new and returning users.

So if the ‘users’ metric includes both new and returning users, then certainly the number of users can’t be equal to the number of unique users (or unique visitors)

So, where are the number of unique users? …….They are missing.

Users != New Users + Returning Users

The total number of users reported by Google Analytics is not equal to the sum of New Users and Returning Users:

This is because Google Analytics also counts new users as returning users if they return within the selected time period. Thus there is an overlap between new and returning users.

A new user can also be labelled as a returning user by Google Analytics.

Google Analytics does not have any ‘Returning Users’ metric

Google Analytics did not create any metric for returning users. It is missing for no apparent reason.

You can only see the ‘New Users’ metric in GA:

Google Analytics does not report on the number of returning users by default

You need to apply a ‘returning users’ advanced segment to see the number or percentage of returning users

Visitor vs User

In the context of Google Analytics, users and visitors are the same things. Both refer to your website visitors. However, there is an exception.

While everywhere else, Google Analytics refers to website visitors as ‘users’, in the New vs Returning report, it categorises website visitors as a ‘new visitor’ and ‘returning visitor’ (instead of a ‘new user’ and ‘returning user’):

In the context of the New vs Returning report, a new visitor is a dimension, and a new user is a metric. Similarly, in the context of the New vs Returning report, returning visitors is a dimension. However, there is no corresponding returning user metric. Google Analytics did not create any metric for returning users. It is missing for no apparent reason. 

You can only see the new user metric in GA. It seems GA couldn’t come up with a unique name for the values of the user type dimension. Had GA used a new user as a dimension name, it would have become impossible to differentiate between the new user dimension and the new user metric.

Client ID and User ID

Client ID is unique to the browser or device, whereas User ID represents a unique logged-in user. The main aim of the Client ID and User ID is to identify the visitors to the website.

However, the main aim of the User ID is to identify users across browsers and devices to provide unique IDs.

Client ID is generated by a Google Analytics cookie and doesn’t need any additional configuration. However, you must make additional configurations in your Google Analytics account to capture a User ID.

To understand more about the difference between User ID and Client ID, refer to this article: Difference between Client ID and User ID.

A person can be counted as a new/returning user more than once

A person can return to your website via different devices or browsers.

Since client ID is not shared between different devices and browsers (by default), the same person can be counted as a new user or returning user more than once by GA.

Also worth noting is that Google Analytics uses two different techniques for calculating users. Consequently, there can be discrepancies in the user count in different reports.

There is also a possibility that the same user is counted twice for different sources/mediums. For example, If a user visits your website from organic search and then later returns to your website via paid search within the selected time period, both organic search and paid search would record a visit from the same user.

You need to be aware of these issues while analyzing your user’s data.

Tips while using the Users metric in Google Analytics

#1. Don’t sum your users:  

From the below image, you can see that on 1st August, we had 1063 users, and on 2nd August, we had 1188 users.

If we add the users on both days together, it comes to 2251, but Google Analytics shows us that the total number of users is 2198. If we subtract the 2198 actual user count shown by Google Analytics from our 2251 manually added sum, then we get a difference of 53 users.

In this case, 53 users have visited your website on both days, and hence Google is not counting them twice.

#2. Don’t consider no. of users = no. of actual persons

Google Analytics users are based on the cookie ID stored in the local storage of a browser.

It is possible that a single person visited your website from multiple devices or multiple browsers on the same device. In this case, every time a person uses a new browser, a new client ID will be generated. But in fact, the person is the same.

#3. Don’t consider that new user means it’s their first time visiting the website.

Often, a user clears their browser cookies, visits your website from incognito mode, or uses different browsers or devices.

In this case, every time Google Analytics identifies a new browser, it assigns a new client ID to the browser even though it’s the same user visiting your website.

Hence it is not wise to consider a new user as a first time visitor to the website.

Other articles you will find useful

#1 How to Add Users Metrics to Standard Google Analytics Reports

#2 Learn about Active Users Report in Google Analytics

#3 Understanding the Difference between Client ID and User ID

Frequently Asked Questions about Google Analytics Unique vs New vs Returning Users Explained in Great Detail

For Google Analytics, a user is a combination of a unique random number and the first timestamp. This combination is called ‘Client ID’. Thus, Client ID comprises a unique random number and the first timestamp. The first timestamp is the time of the first visit by a user or the time when the Google Analytics cookie was first set for the user.

The first time a device (desktop, laptop, smartphone, etc.) or a browser (like chrome, internet explorer) loads your website content, the Google Analytics tracking code creates a random, unique id called the client id and sends it to GA server.

This unique id is counted as a new unique user in Google Analytics. Every time a new id is detected, Google Analytics counts a new user. When Google Analytics detects an existing client ID in a new session, it counts as a returning user.

Google Analytics does not report on unique users anymore. According to Google’s definition: The ‘users’ metric includes both new and returning users. So if the ‘users’ metric includes both new and returning users, then certainly the number of users can’t be equal to the number of unique users (or unique visitors).
So, where are the number of unique users? …….They are missing.

While Google Analytics calls website visitors users everywhere else, in the ‘New vs Returning report’, it categorises website visitors as new and returning visitors instead of new users and returning users.

A new visitor is the same as a new user. But in the context of ‘New vs Returning report’, technically, they are different. The ‘New Visitor’ is a dimension, and ‘New Users’ is a metric. Had Google Analytics used ‘New user’ as the dimension name, it would have become very difficult to differentiate between the ‘New User’ dimension and the ‘New Users’ metric.

A person can return to your website via a different device or browser. Since client ID is not shared between different devices and browsers (by default), the same person can be counted as a new user or returning user more than once by Google Analytics.

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