There is one GA4 setting that gets missed more than any other, affects every single property, and is completely irreversible once the damage is done. GA4's default data retention period is 2 months. If you haven't changed it, your historical data is being permanently deleted — silently, automatically, with no warning from Google.
What Is Data Retention in GA4?
Data retention in GA4 controls how long user-level and event-level data is kept before being automatically purged. It applies to the raw event data that powers Exploration reports, custom segments, and user-level analysis. Standard reports use aggregated data and are not directly affected — but any analysis that requires individual-level data will hit the retention wall.
The two available settings are 2 months (the default) and 14 months. There is no option for longer retention in standard GA4. If you need data beyond 14 months, you need BigQuery export.
What You Actually Lose at 2 Months
- Year-over-year cohort analysis — impossible if user data only goes back 60 days
- Lifetime value reporting — LTV requires user history beyond 2 months for any meaningful calculation
- Long purchase cycle analysis — B2B or high-consideration products often have 60–180 day decision cycles
- Exploration reports — any Explore analysis filtered to users acquired before the retention window returns no data
- Audience building from historical behaviour — users outside the retention window can't be added to new audiences
How to Change the Setting
Go to Admin → Data Settings → Data Retention. Change "Event data retention" from 2 months to 14 months. Click Save. That's it — the change takes effect immediately for all future data collection.
This is the single highest-priority setting change for any new GA4 property. It takes under 30 seconds and the consequences of not doing it compound every month.
When 14 Months Isn't Enough
For properties that need data beyond 14 months — enterprise analytics, long-cycle B2B, or any use case requiring multi-year trend analysis — the solution is enabling BigQuery Export (Admin → BigQuery Links). Once configured, GA4 exports daily event data to BigQuery where it can be retained indefinitely at storage cost. This should be set up from day one on any serious property, alongside the 14-month retention change.
Is Your Property Affected?
GA4 Health Check's Account & Property Setup module checks your data retention setting on every audit — it's one of the first checks we run because the consequences are irreversible. Our comprehensive GA4 audit checklist lists it as a critical item. Run a 60-second audit to confirm your current setting and identify any other configuration issues before more data is lost.
