Last Updated: July 1, 2025

FAQ: Should I track traffic from all subdomains within a single GA4 property via a single data stream or set up individual data streams for each subdomain?

Pros of setting up individual data streams for each subdomain:

» GA4 tracks the data for each subdomain separately, which can be useful if you want to see data specifically for each subdomain rather than combined data for all subdomains.

» GA4 will not double-count the traffic as it uses a unique measurement ID for each data stream. However, if a user moves between subdomains without cross-domain tracking, they may be counted as new users in each data stream.

Cons of setting up individual data streams for each subdomain:

» GA4 will not automatically track traffic across all subdomains within a single property, and you will have to set up cross-domain tracking manually.

» Users moving between subdomains may be counted as new users unless cross-domain tracking is set up.

» Sessions may restart when a user moves between subdomains.

» Setting up individual data streams for each subdomain requires more tracking setup, maintenance and troubleshooting. Audiences, custom dimensions & metrics, events, and conversions are managed separately. Hence increased complexity and higher data management costs.

» Individual data streams for each subdomain can lead to a lack of data continuity, making it harder to compare data over time.

» If different teams are responsible for different subdomains, each team may have their own methods and processes for setting up and configuring data streams, tracking events, and analyzing data, making comparing data from different data streams difficult.

» The inconsistencies in how data is collected and analyzed across subdomains can also make identifying trends and patterns in user behaviour across subdomains difficult.

Since there are more cons than pros, the best practice is to use a single GA4 property with one data stream for all subdomains.

GA4 automatically tracks across all subdomains within a single property as long as they share the same Measurement ID.

Users moving between subdomains retain the same GA4 Client ID, preventing session breaks.

Use the ‘Page Location’ dimension in an exploration report to segment the website traffic based on sub-domains.