Four event sources
In plain English: Start with what GA4 already collects before adding custom events.
Automatically collected events arrive with the base setup. Enhanced measurement can collect web interactions such as page views, scrolls, outbound clicks and file downloads when enabled. Google defines recommended events for common business actions. Custom events cover needs that do not fit those models.
- page_view and session_start: collected automatically
- scroll, click and file_download: enhanced measurement examples
- sign_up, login and purchase: recommended events
Parameters add context
In plain English: The event is the verb; parameters are useful details.
A sign_up event can include method = email. A purchase has documented ecommerce parameters. Custom parameter values often need corresponding custom dimensions or metrics before they are usable in broader reports.
- event: sign_up
- parameter: method = email
Name for meaning
In plain English: Prefer Google's recommended event and parameter names when they match the action.
Consistent names make reports and integrations easier to understand. Avoid creating separate events for every label, page or campaign when a parameter can describe the difference.
Keep in mind: Do not send personally identifiable information in event names or parameters.
Verify before analysis
In plain English: An event appearing is not enough; inspect its parameters and duplication.
Use Realtime for a quick arrival check and DebugView for debug-mode detail. Confirm that one user action creates the intended event once and that required parameters contain meaningful values.