Why is there a mismatch between GA4 conversions and Google Ads conversions in Performance Max campaigns?

Question

I’ve set up GA4 and Google Ads with linked conversions, but my PMax campaign shows 30 conversions in Ads and only 12 in GA4 for the same period. Everything is tagged correctly, and goals are aligned. Is this normal?

Why is there a mismatch between GA4 conversions and Google Ads conversions in Performance Max campaigns?

Answer 1

Yes, this is actually pretty common, and in most cases nothing is “broken.”
The Google Ads vs GA4 conversion mismatch comes from how each platform counts, attributes, and reports conversions, especially with Performance Max.

Why Your PMax Conversions Are Higher in Google Ads

Here are the main reasons you’re seeing 30 in Ads vs 12 in GA4:

1. Attribution Model Differences

• Google Ads uses the attribution model you set in Ads (often data-driven attribution or last click on Google Ads interactions).

• GA4 defaults to cross-channel data-driven attribution (and in many reports, last non-direct click).

• This means Ads might credit a conversion to PMax even if GA4 credits it to another channel (e.g., organic search, direct).

2. Counting Method Differences

• Google Ads: Counts conversions per ad interaction (if one user clicks twice, both can count depending on settings).

• GA4: Counts per user/session (same user converting twice in one session may only be counted once for that goal).

3. Time-of-Conversion vs Time-of-Click

• Google Ads: Attributes conversions to the date of the click that led to the conversion.

• GA4: Attributes to the date the conversion actually happened.

• If there’s a delay between click and purchase, reports will differ.

4. View-Through Conversions

• PMax often drives view-through conversions (user saw your Display/YouTube ad but didn’t click, later converted).

• Google Ads counts these (if enabled).

• GA4 does not, it only counts click-based conversions.

5. Tracking Scope & Tag Placement

• GA4 only counts conversions if the GA4 tag fires on the conversion page.

• Google Ads can still count some conversions via enhanced conversions or offline imports even if GA4 missed them.

Is This Normal?

Yes, it’s completely normal for Ads to show more conversions than GA4, especially with PMax.
For eCommerce with cross-device and view-through activity, Ads can be 20–80% higher than GA4.

How to Get the Numbers Closer

• Make sure both GA4 and Ads use the same attribution model (in Admin → Attribution Settings).

• Align the conversion counting method (one per click vs every).

• If you don’t want view-through conversions inflating Ads numbers, turn them off in Ads settings.

• Use data-driven attribution in both so you’re comparing like-for-like.