Process Flow
Animated overview of the full workflow
TL;DR
Event parameters add context to GA4 events — for example, a 'purchase' event can include parameters for value, currency, items, and transaction_id. GA4 automatically collects some parameters (page_location, page_title, etc.) with every event. You can add custom parameters via GTM or gtag.js. Register custom parameters as custom dimensions or metrics in GA4 Admin to use them in reports and explorations.
Step-by-Step Guide
Follow these 4 steps to complete this guide
- 1
Automatically Collected Parameters
Every GA4 event includes: language, page_location, page_referrer, page_title, screen_resolution. These appear in reports without any configuration.
- 2
Adding Custom Parameters
In GTM, add parameters to your GA4 Event tag under 'Event Parameters.' Enter parameter name and value (can be a GTM variable). In gtag.js, include parameters in the event call: `gtag('event', 'generate_lead', {'lead_source': 'contact_form', 'value': 100});`
- 3
Registering Custom Dimensions/Metrics
To use custom parameters in reports, register them: Admin > Custom definitions > Create custom dimension. Enter the parameter name exactly as it appears in your event data. Select the scope (Event or User). It takes 24-48 hours for data to appear after registration.
- 4
Best Practices
Use snake_case naming. Be consistent across events. Register only parameters you need in reports (there are limits). Use standard e-commerce parameters for purchase-related events.
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