Content revised 21 October 2026.
An event records a measured interaction. Plan what the event means before deciding how to collect it or whether to mark it as important.
Define the interaction
Describe the action and success condition in plain language. Separate a link click from a completed enquiry. Decide which parameters are useful and avoid sending personal information that should not enter analytics.
Review existing events
Check automatically collected and enhanced measurement events before adding custom code. Duplicate implementations can inflate the data. Use recommended event conventions where they fit the actual task.
Test the implementation
Trigger a safe example and inspect received data. Check that the event fires once under the intended conditions and does not fire on a failed action. Include mobile and relevant cross-domain steps in the plan.
Maintain the definition
Record the trigger, parameters, owner and release date. Key-event status should follow business importance, not a desire to make the report look stronger. Recheck collection after significant website changes.
Official guidance: GA4 enhanced events.