Data Discrepancy Between GA4 & Google Ads

Shopify Discussion

AI-generated summary

Significant conversion discrepancy between Google Analytics 4 (GA4) and Google Ads after importing GA4 purchase conversions into Google Ads for a Shopify store. In September, GA4 attributes 1,104 purchases to Google Ads campaigns, while Google Ads shows 226.09 imported conversions.

Setup details: Shopify sends purchases to GA4; GA4 is linked to Google Ads; the imported conversion is Primary, counts every conversion, uses a 90‑day click‑through window, and both platforms use data‑driven attribution including paid and organic channels. The poster is concerned optimization is based on incomplete data and shared a Loom video with examples.

Suggested causes from the response (no definitive fix provided):

  • Date ranges in GA4 may include periods before accounts were linked.
  • Multiple Google Ads accounts linked to the same GA4 property can complicate reporting.
  • Google Ads and GA4 use different calculations and attribute clicks vs. sessions differently.
  • Reference documentation provided: Google support article on Analytics–Ads discrepancies.

Status: No resolution yet; next steps are to review linkage, date ranges, and attribution settings per Google’s guidance.

1

I have connected Shopify to GA4 to report purchases. I have also linked GA4 to Google Ads. I’m importing purchase conversions from GA4 into Google Ads; however, purchases aren’t matching. I recorded a Loom to show examples of the reporting discrepancies between GA4 & Google Ads: https://www.loom.com/share/5e701c63ce094baa92a0670f3f61f76e?sid=e4f3a30b-76c1-4725-9320-245a5773a55d

For example, in September I’m reporting:

GA4: shows purchases attributed to Google Ads campaigns as 1,104

Google Ads: shows purchases imported from GA4 as 226.09

My Google Ads conversion that is imported from GA4 is set as Primary. I have it set to count every conversion. The Click-through conversion window is 90 days (managed in GA4).

Both Google Ads and GA4 use Data-driven attribution and are counting Paid and organic channels.

Any ideas on how to troubleshoot why these purchase numbers are so far apart? I’m likely optimizing Google Ads campaigns with incomplete purchase data.

2

Hello Emilydrumm,

Thanks for reaching out to the community!

The Google Analytics Reports and Google Ads Reports import the required data directly from the Google Ads system, and usually the results are the same, but sometimes they can differ, as:

  1. Google Analytics compares long date ranges, which may include the data when the account wasn’t linked yet
  2. When multiple Google Ads accounts are linked to the same Google Analytics account, the information on the reports gets complicated
  3. Google Ads performs different calculations than Analytics, which may result in some differences in the final results of the reports.
  4. Moreover, Google Ads and Google Analytics calculate clicks and sessions differently

To read about it in detail, please refer to this article - https://support.google.com/analytics/answer/1034383?hl=en#zippy=%2Cin-this-article

Hope it helps!

Leesha

SEOKart