The number of users in a Google Analytics audience may differ from the number of users in the same audience when exported to Google Ads and other Google products. This article explains reasons why there may be differences in user counts across products. For all the reasons listed below, we do not expect audience list sizes in Google Analytics reporting to match audience list sizes in integrated Ads products, or user counts in the Analytics Data API.
In this article:Identity spaces
User reporting in Google Analytics is based on the Google Analytics client ID for web traffic, and the app-instance ID for app traffic. Users are also de-duplicated in Google Analytics reporting based on User ID, when the feature is enabled.
For audiences exported to Google Ads, different identifiers are counted. These identifiers are required to match users during advertising serving time. There can be multiple cookies associated with one GA4 client ID (web), or app-instance ID (app). There can also be zero advertising cookies associated with a GA4 user identifier, for reasons like consent.
- On Web: Google Analytics exports advertising cookies associated with the GA4 client ID.
- On App: Google Analytics exports the app-instance IDs.
End-user consent and ads personalization preferences
In Google Analytics, the size of an audience represents the number of users who meet the audience criteria. In Google Ads and other advertising products, the size of a Google Analytics audience reflects only the remarketable portion of this group.
Both Google Analytics users and end users can apply ads personalization preferences in multiple ways. These ads personalization preferences impact how users are counted in Google advertising products like Google Ads, but not in Google Analytics. This section describes some examples of ads personalization configurations that can lead to discrepancies between products.
Google Analytics settings
Google signals and user-provided data collection
Having either Google signals or user-provided data collection enabled is required in order to export audiences to Google Ads and built-in Google integrations. Analytics audiences exported to Ads only include users who interact with a website or app while Google signals are turned on. Data collected during periods when Google signals are turned off isn't incorporated in audiences exported to other Google products.
It is possible to turn on Google signals for some regions, while keeping it turned off for others. Data collected from regions where you have turned off Google signals will not be included in audiences exported to Google Ads or other Google products. Learn more about regional ads personalization settings.
Property settings
Advertisers can enable or disable personalized advertising at the property level using the data controls in Google Analytics. Google Analytics users can also do this for specific events, and user-properties. The advanced setting allows for ads personalization to be enabled or disabled regionally, for users coming from any or all supported countries and/or US states.
Tag configuration settings
Similarly, property administrators can opt out of allowing the use of Analytics data for ads personalization entirely or partially, through Google Analytics tagging implementation adjustments. This can be done on Web Tags and SDK Configuration.
Ads personalization for a linked Google Ads account
In addition to the property-level ads personalization settings, you can turn on or turn off Ads personalization in Analytics for a particular linked Google Ads account. For audiences to be sent to Google Ads, Ads personalization must be enabled on the link between a Google Analytics property and a Google Ads link. It is enabled by default when you link a Google Ads account to Analytics. Learn more about controlling ads personalization for a single Google Ads link.
After you establish a connection with an advertising platform, such as Google Ads and activate ad personalization, we generate the audience list incorporating data from the previous 30 days. If the integration with an ad platform and the activation of ad personalization occur more than 30 days after you create the audience, the audience list data in Google Analytics won't align with the audience list data in Google Ads.
Granular location and device data
Collecting granular location and device data can also affect the data exported to other Google products. If you have this setting disabled, Google Analytics will not collect several dimensions (City, Device brand, and others). Any audiences built using these dimensions will be inaccurate.
End-user settings
Google Account configuration settings
Users logged into their Google Account can configure their ads personalization preferences at their Google account level in My Ad Center, which then applies when they navigate websites/apps logged with their Google Accounts.
Operating system-level configuration settings
Some operating systems, like Android 4.4 and older, allow an end user operating system-level configuration for ads personalization, limiting personalized advertising data collection. Learn more about advertising identifiers for mobile apps.
Consent mode
If you implement a consent banner asking for permission to store ads or analytics data, users who visit your site or app can choose to opt out. If users choose to opt out of ads data storage, they are ineligible for remarketing campaigns. Nevertheless, if they've agreed to analytics storage, they may still appear in your Google Analytics 4 reports, but they won't be included in the count for any linked advertising services.
ATT consent
With Apple's iOS 14 update and its App Tracking Transparency (ATT) policy, many advertisers have chosen to implement the ATT prompt to ask for permission to use certain information for advertising purposes in a compliant manner. If a user denies the ATT consent prompt, device identifiers required for remarketing are not collected, and the user is not eligible for remarketing purposes. As a result, the user may appear in Google Analytics 4 reports, but they won't be included in the user count for linked advertising services.
Additional reasons for differences
Backfilled audiences
When you create an Audience in Google Analytics and enable Google Ads remarketing, Google Analytics backfills that audience in Google Ads with recently added members. However, Google Analytics reports and audience lists do not contain backfilled audience memberships. A user will need to log an event after the audience is created for reports and audience lists to show the user in that audience.
For example if a user logs a purchase event on June 20th and you create a "Purchasers" audience on June 21st, then you likely need to wait until June 22nd to potentially find that user in new audience lists. However, that user will only be in the audience list if the user has logged any event on June 21st.
After you establish a connection with an advertising platform, such as Google Ads and activate ad personalization, we generate the audience list incorporating data from the previous 30 days. If the integration with an ad platform and the activation of ad personalization occur more than 30 days after you create the audience, the audience list data in Google Analytics won't align with the audience list data in Google Ads.
Data freshness
The time it takes Analytics and Google Ads to collect and process events and update audiences is called data freshness. Freshness time may differ between Analytics and other Google products. In the time between when the audiences are updated for one product, but not updated for the other product, there may be some data differences. Learn more about Data freshness.
Data import
For user data imported via GA4 User Data Import, only active users are included in the audience list sizes reporting in GA4, such as the GA4 Audiences Report. However, the user data is included in export destinations like Google Ads.
Where there may be differences
User count reporting across surfaces
The following example illustrates the user count differences you may see across surfaces. If you created a property in January of 2019, but you created a user list of "All Users in Japan" in January of 2020:
- Export to Google Ads: The audience list exported to Google Ads would only include users from January 2020 moving forward, plus 30 days of backfilled users.
- Audience pre-population, as the full list of users meeting the audience criteria in the 30 days before the audience was created, is relevant only for integrations like Google Ads where the full list of users is sent. This discrepancy only occurs if the membership duration is over 30 days.
- Analytics reporting for user metrics in explorations and reports: If you created a property in January of 2019, and you looked at All Users in Japan since January 2019, it would show all users for the lifetime of the property. User count reporting in Analytics reflects the users for the lifetime of the property collecting data.
- Audiences management table and linked Analytics reports: The audience list counts found in the management table in Admin > Data display > Audiences would only include "All Users in Japan" from the date the audience was created (January 2020 in this example), moving forward. It would not include the 30 days of backfilled users. The audience reports that you can access either from the management table or by clicking the name of a specific audience from the Audiences report work the same way.
- Audience estimates in the audience builder: The summary card in the Google Analytics audience builder estimates the number of users who fit your chosen criteria over the past 30 days. These estimates are meant to give you an idea of how many people might be in your audience based on the data from the last 30 days. These estimates do not align with the number of users exported to Google products. For example, if a user is marked as not eligible for use for ads personalization, the user would not be present in Google Ads audience lists.
