Key Event

A key event is an event you've flagged as important to your business — a form submission, a purchase, a booked call. In 2024 Google renamed "conversions" to "key events" in the standard reports, so the thing you mark as a key event is exactly what most people still call a conversion. You create one by toggling an existing event on in the Admin section.

Why it matters

Out of the box, GA4 measures hundreds of events, but only a handful represent something you actually care about. Marking those as key events is what separates signal from noise: it tells GA4 which actions to count in the reports that matter, and it's the foundation for measuring whether your site does its job.

A concrete example

Say your goal is contact form submissions. GA4 already fires a form_submit event, but it's buried among everything else. You go to Admin, find that event, and flip the "Mark as key event" toggle. From then on, GA4 counts each submission as a key event, and you can finally see — week to week — whether more or fewer people are reaching out. For a fuller treatment of the conversion side, see Conversion (Key Event).

The common misreading

The biggest mistake is assuming key events are retroactive. They are not. If you mark an event as a key event today, GA4 only starts counting it as one from today forward — historical data isn't reclassified. People who switch on a key event and then compare to last month often see a phantom "increase" that's really just the metric not existing before. Always note the date you flagged it.