Cross-domain tracking in Google Analytics 4 (GA4) pertains to monitoring users and their interactions across multiple domains.

By default, GA4 lacks the capability to monitor users and their interactions across different domains due to its utilization of first-party cookies, which are restricted to the domain of origin. Consequently, implementing cross-domain tracking must be done manually.

Cross-domain tracking becomes necessary in Google Analytics 4 when your session extends across multiple domains, aiming for Google Analytics to recognize sessions across various domains as one cohesive session.

Lacking cross-domain tracking setup, you’ll encounter difficulty in comprehending and monitoring a user’s journey across multiple domains.

Consider a scenario where you operate two distinct websites, each equipped with its own individual GA4 properties.Your aim is to establish cross-domain tracking between these sites.

Given Google’s recommendation to employ the same GA4 property and web data stream for cross-domain tracking, and considering your current setup with separate GA4 properties for each domain, integration into a single GA4 property becomes necessary.

Essentially, this entails reinstalling GA4 tracking for one of the domains involved in cross-domain tracking to ensure both domains utilize the same measurement ID.

However, this approach may not be feasible for many users who prefer maintaining separate GA4 properties for each domain and may find consolidation solely for cross-domain tracking impractical.

As an alternative, rather than merging two GA4 properties into one and reconfiguring GA4 tracking for one domain, it’s advisable to establish a third GA4 property exclusively dedicated to cross-domain tracking purposes.

If you encounter difficulties configuring cross-domain tracking or seek expert assistance in setting up your Google Analytics 4 (GA4) properties, conducting audits, testing cross-domain tracking, or visualizing data from multiple domains within the same data stream, feel free to reach out to SmartLi