[GA4] Detailed Explanation of the Causes and Solutions for (not set) Appearing in Reports

February 4, 2025

When analyzing data in GA4, you may often encounter "(not set)" appearing in your reports. This can occur due to the combination of dimensions and metrics used or as a result of how users interact with your website. However, by reviewing and adjusting your GA4 settings, you can reduce the occurrence of (not set).

In this article, we will clearly explain the main causes of (not set) and the measures you can take to address them.

What Does (not set) Mean in GA4?

When analyzing data in Google Analytics 4 (GA4), you may come across the value (not set) in various dimensions. This occurs when GA4 is unable to retrieve the correct value for a given dimension and instead assigns a default placeholder value.

There isn’t a single cause for (not set) to appear. The reasons can vary depending on measurement settings and the way data is sent to GA4.

Main Causes of "(not set)" in GA4

The main reasons why "(not set)" appears in GA4 are as follows:

Improper data collection settings (e.g., tags are not configured correctly)
Dimension values are not assigned at the start of a session
Issues with redirects or query parameters
Custom events or automatic tracking are not set up correctly

In the following sections, we will take a closer look at the causes and solutions for each specific dimension.

When the Landing Page Dimension Appears as (not set)

The landing page is the page where the first page_view event occurs in a session. Therefore, if no page_view event occurs in a session, there is no corresponding landing page, and it will be displayed as (not set).

Let's explain the specific user actions that can result in the landing page being (not set). Suppose a user performs the following actions:

Views Page A (a page_view event occurs).
Leaves the site idle for more than 30 minutes or views another site in a different tab for more than 30 minutes.
Scrolls on the still-open Page A (a scroll event occurs).
Closes the tab and exits the site.

In GA4, the default session timeout duration is 30 minutes. This means that if no interaction occurs on the site for 30 minutes, or if the user remains inactive on the site while viewing another site in a different tab for more than 30 minutes, the session will expire. When the user returns to the site, a new session will start.

In the example above, step 2 causes the session to expire, meaning that steps 1 and 3–4 belong to different sessions.

In the session at step 1, a page_view event occurs on Page A, so Page A is recorded as the landing page.
However, in the session at steps 3 and 4, no page_view event occurs, meaning there is no corresponding landing page, resulting in (not set).

As shown in this example, the occurrence of (not set) in the landing page dimension is a result of GA4’s specifications, and to some extent, it is unavoidable.

When Google Ads Dimensions Are Displayed as (not set)

In GA4, you can also view data related to Google Ads. There are several possible reasons why Google Ads dimensions may be displayed as (not set).

If the Google Ads account and Analytics property are not linked

If GA4 and the Google Ads account are not linked, advertising dimensions (e.g., campaign name, ad group, etc.) cannot be retrieved correctly. Therefore, it is important to properly set up the link between GA4 and Google Ads to ensure accurate tracking. Below, we will introduce the steps to link GA4 with Google Ads.

First, go to the Admin menu in GA4, then navigate to Product Links > Google Ads Links.

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Next, click the link button in the upper right corner.

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The settings screen will be displayed, so select the Google Ads account you want to link. You can link up to 20 Google Ads accounts to a single GA4 property.

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Set up the account and click the submit button.

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If the linked account is displayed as shown in the screen below, the setup is complete.

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Auto-Tagging is Not Enabled

If the destination URL of a Google Ads link does not include auto-tagging (gclid), GA4 will not be able to identify ad information. In this case, check the settings in Google Ads. Go to your Google Ads account settings and verify whether "Auto-tagging" is enabled. If it is disabled, change the setting to enable it.

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The landing page URL has been manually tagged with incomplete or incorrect UTM parameters.

When UTM parameters are manually added to an ad URL, “(not set)” may appear if the parameters are not configured correctly. Since there are clear rules for setting UTM parameters, be sure to follow those rules when adding them.

Traffic from Unlinked Google Ads Accounts

If you are managing multiple Google Ads accounts, traffic from unlinked accounts may be recorded as (not set) in GA4. You can link up to 20 Google Ads accounts to a single GA4 property, so make sure to link all the accounts you are using to ensure accurate tracking.

When the Session Source / Medium Dimension Appears as (not set)

If a session does not trigger the automatically collected session_start event, it will be reported as "(not set)" in the Session Source / Medium dimension.

This often occurs due to misconfigurations in GA4 settings. Common causes include:

The user navigates to a checkout page or another domain during the session, but that domain has not been added to the referral exclusion list.
The user lands on a page within the same site where the GA4 tag is not implemented, then returns to a tagged page.

To resolve this issue:

Ensure that all pages on your site have the GA4 tag properly set up.
If necessary, add domains to the referral exclusion list.

Steps to Configure Referral Exclusions in GA4

Open Admin in GA4.
Navigate to Data Streams and select the appropriate data stream.

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Click on "Configure tag settings" to continue.

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Click on the "List unwanted referrals" menu.

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Set the domain information of the referral source you want to exclude, then click "Save" in the upper right corner.

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The referral exclusion settings have now been configured.

When the Content Group Dimension Appears as (not set)

When combining the content group with default events such as session_start or first_visit, the content group dimension may appear as "(not set)." This happens because default events do not accept the content_group parameter.

Additionally, even if an event sends the content_group parameter, "(not set)" may still appear if the value is empty (e.g., content_group: "").

Therefore, if you are using the content group dimension set in GA4, ensure that the parameter is not being combined with default-collected events and that the content group is correctly configured.

When a Custom Parameter Appears as (not set)

One possible reason for this issue is that the custom parameter used in the event is not configured correctly. Additionally, within the first 24 hours after registering a custom parameter, its value may be displayed as (not set) by default.

Therefore, check again after more than 24 hours have passed. If (not set) is still displayed, review the configuration conditions of the custom parameter to ensure there are no mistakes.

Summary of Measures to Reduce (not set) in GA4

As we have seen so far, many occurrences of (not set) in GA4 are due to misconfigurations within GA4 itself. While some instances of (not set) appear due to the combination of dimensions and metrics, making it impossible to eliminate them entirely, you can take the following steps to reduce their occurrence: