Google Tag Manager (GTM) has released an important update for professionals interested in digital analytics and marketing integrations. Access to critical user and session data related to GA4 is now provided by GTM's native capabilities instead of manual solutions.

This update significantly enhances the reliability of data flows by standardizing processes that have long been managed by fragile Custom JavaScript code.

Strategic Benefits of the Update: Why is it a Turning Point?

The core identity data of GA4, including Client ID, Session ID, and Session Number, is vital for Conversion API integrations, CRM data mapping, and advanced segmentation.
Beyond technical ease, this update brings the following benefits to strategic business processes:

1. Increase in Data Reliability

Custom JavaScript codes previously used to access data were (Custom JS) vulnerable to potential changes in GA4's cookie structure. This posed the risk of disrupted data flows or erroneous data collection.

New Built-in Variables guarantee stable access independent of Google’s infrastructure changes, as they pull data directly through GTM’s secure APIs.

2. Increased Integration Speed and Efficiency

When critical identity data (like Client ID) needs to be transferred to third-party platforms (Meta, TikTok, etc.), analysts and developers can pull data instantly instead of spending time parsing cookies. This increases the agility of marketing actions by enabling faster and error-free deployment of conversion APIs and server-side tagging.

3. Scalable Structure

In complex setups where multiple GA4 properties are managed, the newly added Analytics Storage variable type comes into play. This feature clarifies which Measurement ID (Measurement ID) the data focuses on, raising the standard of data isolation and management in various analytical projects conducted for different projects.

What are the New Built-in Variables?

To provide these benefits, GTM has added three critical Built-in Variables (Built-in Variable) to the Configuration field:

• Analytics Client ID: The user's persistent, unique identity.

• Analytics Session ID: The unique session ID associated with the user's current session.

• Analytics Session Number: Data indicating which session the user is currently on while visiting the website.

Considerations

For these variables to work correctly, it is a prerequisite for a Google Tag(gtag.js) code to be functioning on the website. All setups using the standard GTM GA4 Configuration Tag naturally meet this requirement.

This GTM update modernizes the access process for GA4 data, enabling analytics professionals to establish more reliable, standardized, and easy-to-maintain integrations.

It is now possible to seamlessly and securely integrate core identity data into the marketing technology stack without carrying the risk of custom code!