Cross Domain Tracking: When It's Important To Implement It

Problem of Multiple Domains

By default, GA4 utilizes first-party cookies to track user behavior. These cookies are specific to each domain and cannot be shared across different ones. Consequently, if a user journeys between two separate domains (abc.com and xyz.com), GA4 on xyz.com wouldn't recognize them as the same visitor who previously interacted with abc.com. This leads to below mentioned issues:

1. Increased user count: Each domain would register the user as a separate individual, increasing your total visitor numbers.
2. Inaccurate session data: Session continuity across domains wouldn't be captured, providing an incomplete picture of user journeys.
3. Misleading traffic sources: GA4 might misinterpret visits from one domain to another as internal referrals, distorting your traffic acquisition insights.

Read More: Third-party cookies are going away, and it's time to prepare for a cookieless future

Understanding What is Cross-domain Tracking

Cross-domain tracking in Google Analytics 4 serves as a solution, allowing you to bridge the gap between separate domains and ensure a unified view of user activity. It facilitates the transfer of user identifiers from one domain to another, enabling GA4 to recognize users across platforms and maintain session continuity. Unlike the complexities involved in Universal Analytics (UA), GA4 simplifies the configuration process, making it more accessible to marketers and analysts.

How Cross-domain Tracking Works in GA4

When a user navigates from abc.com to xyz.com, GA4 appends a special parameter (_gl=) to the URL of xyz.com. This parameter contains information about the user, enabling GA4 on xyz.com to identify them as the same individual who interacted with abc.com.

Subdomains and Cross-domain Tracking

It's important to note that you don't need to implement cross-domain tracking for subdomains belonging to the same domain (e.g. blog.abc.com and www.abc.com). GA4 automatically tracks user activity across subdomains within a single domain.

Configuring Cross-domain Tracking in GA4

Prerequisites:Both domains must utilize the same GA4 property and data stream. This signifies they share the same measurement ID.

Navigate to: Admin > Data Streams and select the relevant web data stream.

Configure Tag Settings: Under Configure Tag Settings, click on "Configure your domains."

Enter Domains: Include all domains you wish to be part of the cross-domain tracking setup. Click "Save."

Testing: Once configured, verify this setup by clicking a link on abc.com that redirects you to xyz.com. Check the URL of xyz.com; it should contain the _gl= parameter.

Additionally, you can utilize the GA Debugger extension to further validate if user activity is being tracked accurately across domains.

Additional Considerations:

Referral Exclusion List: GA4 automatically manages self-referrals based on the configured domains. However, the referral exclusion list is still relevant for excluding specific domains like payment gateways from being counted as referral sources.

Redirects and Parameter Preservation: Ensure redirects between domains preserve the _gl= parameter. Identify and troubleshoot any issues with parameter loss during redirects chain loops

Conclusion:

Cross-domain tracking in GA4 offers a streamlined approach compared to previous versions of Google Analytics.expand_more It simplifies the configuration process, requiring minimal adjustments within the GA4 interface, reducing reliance on code-level or GTM modifications.

Like | Follow | Share