Discrepancies between Google Analytics 4 and Looker Studio

Looker Q&A Looker
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1

Hi everyone,
I’m noticing a consistent discrepancy between Google Analytics 4 (GA4) and Looker Studio when reporting sessions. For example, for the last 7 days:

GA4 UI shows: 280,000 sessions

Looker Studio shows: 295,000 sessions (using the GA4 connector, no filters applied)

The same happens when looking at larger time ranges (e.g. full month).
All filters, dimensions, and metrics are aligned, i’m using the default “Sessions” metric

I understand there can be slight differences due to API behavior or data processing delays, but I’d appreciate:

  • A clear explanation of what causes this difference
  • Whether there is a best practice to minimize it
  • Whether the Data API (used by Looker Studio) calculates sessions differently than the GA4 UI

Thanks in advance!

2

Nice, not a single person could help me, not even the Staff. Looker is truly abandoned.

3

Hi, I was troubleshooting a data discrepancy on total page views, and found that I needed to change my filter in Looker Studio from “page path” contains to “page path and query string” contains to match up with the GA4 interface better. There’s also this lengthy resource: https://measureschool.com/data-discrepancies-between-ga4-and-looker-studio/

4

GA4’s UI and Looker Studio don’t always count sessions the same way. The GA4 interface uses pre-aggregated tables and applies processing rules a bit differently than the GA4 Data API (which Looker Studio relies on), so small gaps are common. For a reliable cross-check, compare page_view counts first or validate with a BigQuery export if available.

I ran a quick audit using GAfix.ai, which helped verify data stream mismatches — but you can use any GA4 audit tool to save time tracking this down.