Setup User-ID in Google Analytics 4 (GA4) using Google Tag Manager

User ID is a unique identifier that you can assign to a user in Google Analytics 4 (GA4) to track a user’s interactions across multiple devices and sessions. A User ID can be any unique identifier that you choose to assign to a user, such as an email address, username, or customer ID. By tracking a user’s interactions with your website or app with a User ID, GA4 can provide more accurate user-level data and provide insights into cross-device and cross-session behavior.

User ID in Google Analytics 4 (GA4) can also be tracked as a custom dimension. A custom dimension is a piece of information that you can add to your GA4 data to provide additional context and insights. 

User ID in Google Analytics 4 (GA4) can also be tracked as a custom dimension using the data layer in Google Tag Manager (GTM). A custom dimension is a piece of information that you can add to your GA4 data to provide additional context and insights. To track User ID as a custom dimension in GA4 with the data layer in GTM:

• In the GA4 property, go to the Custom Definitions section and create a new custom dimension with the name “User ID”.
• Create a data layer variable in GTM to store the User ID
• Push the User ID to the data layer using the following code:

window.dataLayer = window.dataLayer || [];
window.dataLayer.push({
  'userId': '{{User ID}}'
});

Replace “user ID” with the actual user ID.

The “user_id” parameter in the config command is typically used to identify the user or device associated with a measurement. It allows the measurement code to associate a specific measurement with a unique user or device, allowing you to track user behavior, performance, or other metrics over time. The exact implementation of the user_id parameter may vary depending on the measurement code and the platform it is being used on, but it is commonly used in tracking and analytics applications to provide better insights into user behavior.

Disclaimer: Google tag manager belongs to Google property 

For Contact: mappchero@gmail.com

I am available for Hire on Freelancer: Freelancer.com

I am available for Hire on Upwork: Upwork.com

I am available for Hire on Peopleperhour: Peopleperhour.com

I am available for Hire on Guru: Guru.com