How to Implement Custom Parameters in GA4 Using Google Tag Manager

To implement custom parameters in GA4 using Google Tag Manager (GTM), follow these key steps:

1. Create or Edit a GA4 Event Tag in GTM

   • In GTM, create a new tag or edit an existing GA4 event tag.
   • Choose the GA4 Event tag type and link it to your GA4 Configuration tag.
   • Name your event (e.g., purchase, sign_up, or a custom event name).

2. Add Custom Parameters in the Event Tag

   • Within the tag settings, find the Event Parameters section.
   • Add your custom parameters as key-value pairs, for example:
     • Parameter Name: product_id
     • Value: {{DLV - Product ID}} (a GTM variable or static value)
     • Parameter Name: membership_level
     • Value: gold
       These parameters provide additional context to your events.

3. Publish the Container

   • Save and publish your GTM container to deploy the changes.

4. Register Custom Parameters as Custom Dimensions in GA4

   • In GA4, go to Configure > Custom Definitions.
   • Create a new custom dimension with the exact parameter name used in GTM (e.g., product_id).
   • Set the scope to Event and save. This step allows GA4 to recognize and report on your custom parameters.

5. Use Custom Parameters in GA4 Reports

   • Use the Explore section in GA4 to build custom reports or analysis using your new parameters.
   • Filter or segment data by these parameters to gain detailed insights.

Additional best practices:

• Use clear, descriptive names for parameters to avoid confusion.
• Avoid over-tracking to maintain data quality.
• Document your tagging plan for scalability and maintenance.

This approach leverages GTM’s flexibility to send detailed event data to GA4, enhancing your analytics capabilities with custom insights tailored to your business needs.