Illuminate the Data: Understanding GA4's Identity Reporting

5th Jul 2024

4 Minutes Read

By Anshul Dhurandhar

In the ever-evolving world of digital analytics, Google Analytics 4 (GA4) stands as a powerful tool for understanding user behavior across devices and platforms. But within this robust platform lies a crucial concept that can sometimes feel like a labyrinth: Reporting Identity. This blog serves as your guide, helping you navigate the intricacies of Reporting Identity in GA4 and ensure your data reflects the true customer journey.

What is Reporting Identity in GA4?

Reporting Identity is the method GA4 uses to identify and link user interactions across different touchpoints. This is crucial because users often interact with your website or app on various devices, making it challenging to paint a holistic picture of their journey. GA4 offers three primary Reporting Identity options:

  1. Device-Based: This method relies solely on the device ID, a unique identifier assigned to a user's device (e.g., smartphone, computer). While simple, it fails to capture user behavior across different devices.

  1. Observed: This option prioritizes observable data in the following order: User ID (if available) and Device ID. Here's a breakdown:
  • User ID: A unique identifier you assign to users, often linked to their account login. This offers the most accurate method for cross-device tracking (if users are logged in).
  • Device ID: A unique identifier assigned to a user's device (e.g., smartphone, computer).

  1. Blended (Default): This is the default option in GA4 and utilizes a hierarchical approach:
  • User ID (highest priority)
  • Google Signals (if User ID is unavailable and Google Signals are enabled/opted-in)
  • Device ID (if neither User ID nor Google Signals are available)
  • Modeling (as a last resort, GA4 attempts to model user behavior based on available data)

Choosing the Right Reporting Identity

The optimal Reporting Identity for your needs depends on several factors:

  • Data Privacy Regulations: Some regulations might restrict the use of User IDs or Google Signals.
  • Website/App Login System: If you have a robust login system with User IDs, utilizing this option can offer the most accurate cross-device tracking.
  • Google Signals Opt-In Rates: If a significant portion of your users opt into Google Signals, leveraging this data source can enhance cross-device tracking.
  • Technical Expertise: Implementing User IDs requires additional technical setup.

The Impact of Reporting Identity on Your Data

The Reporting Identity you choose will directly influence the data you see in your GA4 reports. Here are some key considerations:

  • Device-Based: This method underestimates user engagement, as it fails to capture cross-device activity.
  • Observed: This option provides a more accurate picture, but its effectiveness relies on User ID availability and Google Signals opt-in rates.
  • Blended (Default): This offers a balanced approach, but might still underestimate cross-device activity if User ID implementation or Google Signals adoption are low.

Best Practices for Reporting Identity

Here's how to ensure your Reporting Identity setup is optimized for accurate data capture:

  • Evaluate Your Needs: Carefully consider your data privacy regulations, login system, and technical capabilities to choose the most suitable Reporting Identity option.
  • Implement User IDs (if applicable): If you have a login system, consider implementing User IDs to enhance cross-device tracking accuracy.
  • Monitor and Refine: Regularly monitor your data and adjust your Reporting Identity strategy based on your findings.
  • Educate Yourself: Stay updated on the latest developments surrounding Reporting Identity in GA4 and adapt your approach accordingly.

Advanced Techniques for Enhanced Tracking

GA4 offers additional tools to improve user identification beyond Reporting Identity:

  • Customer Matching: This allows you to anonymously link user IDs from your CRM system with online user IDs collected through GA4.
  • Enhanced Ecommerce with User ID: If you have an online store with GA4 Ecommerce tracking enabled, you can leverage this feature to associate user IDs with purchases, providing a more comprehensive view of the customer journey.


Reporting Identity plays a crucial role in ensuring your GA4 data reflects the true customer journey. Understanding the different options, their impact on your data, and implementing best practices empowers you to make informed decisions about your website/app and marketing strategies. Remember, a well-defined Reporting Identity strategy is the key to unlocking the full potential of GA4 and gaining a deeper understanding of your users.