Google Analytics 4 (GA4) is the latest version of Google's analytics platform. It replaced Universal Analytics (UA) starting 1 July 2023, when the standard Universal Analytics properties stopped processing data (1 July 2024 for UA 360 properties). It's critical that you migrate your UA property to Google Analytics 4. Learn how to get started.
When migrating to GA4, you may notice discrepancies between your UA conversion data. This article explains the main differences in essential metrics between GA4 and UA, why these conversion discrepancies occur and tips on how to minimise them.
Before you begin
If you haven't yet replaced your UA conversions with GA4 conversions in Google Ads, follow these steps to replace them with GA4 conversions. Not updating your conversion settings may disrupt your campaigns and affect your campaign's performance. To facilitate this transition, we recommend that you take the following actions:
- First, import your GA4 conversions into Google Ads. If you still have active UA conversions recording events, ensure the imported GA4 conversions are marked as 'secondary' conversion actions to avoid double counting.
- Next, compare your GA4 conversions with the equivalent UA conversions that they’ll replace. You should do this in Google Analytics and Google Ads. Confirm that the GA4 conversion count is as close as possible to your UA conversions. If your UA conversions are no longer recording events, you may need to look at historic data to complete this step.
- Finally, set your GA4 conversions to 'primary' in Google Ads.
Sources of discrepancy
There are important differences between UA and GA4 that may make it difficult to compare your data and conversions. These are the main reasons for discrepancy:
- Inherent differences between UA and GA4:
GA4 properties have a different data model than UA properties. GA4 collects events instead of hits, and uses AI-powered solutions, like behavioural and conversion modelling to support new privacy-preserving technologies. These solutions give you a complete view of performance without compromising user privacy, but they're not available in UA properties.
Learn more about the Difference between UA and GA4.
- Differences in setup and settings:
UA vs. GA4 tag coverage, tag firing conditions, conversion count, filters and URL parameter exclusions can all affect conversions.
Learn how to Fix differences in set up and settings.
Next steps
After you have set up data collection for your websites and apps you can:
