Less GA4 data after implementing Google Consent Mode v2

If you’re implementing Google Consent Mode v2, even if it’s in Advanced mode, you might see a drop in data in Google Analytics 4 (GA4). If it’s the first time you are incorporating end-user consent by using a Google-certified CMP like the Usercentrics CMP, then the data decrease might be steep initially.

Using Google Consent Mode can be challenging at first. Once you’ve familiarized yourself with it, though, how it works and how to best use it become much more straightforward.

We recommend reading our Google Consent Mode (GCM) tech doc and using our GCM Support Knowledge Base when setting up Google Consent Mode.

Why does this GA4 drop in data happen? What can be done to reverse it?

Reasons why you may be seeing less data in GA4

• Your Google Consent Mode implementation may have been done incorrectly.

  • Suggestion: Check your GCM implementation, for example, using Google’s Tag Assistant. We also outline some other methods on our GCM Support Knowledge Base.

• When using Basic Google Consent Mode (GCM), the issue can simply be that the tags of the relevant Google services are blocked until end-user consent is obtained. As a result, you fully depend on your users' consent decisions before any tracking can occur with Google tags.

  • Improvement options:

    • Explore using Advanced GCM. We recommend aligning with your Data Protection Officer (DPO) and/or legal counsel to make this decision. You can find more information here: Differences between Advanced GCM V2 and Basic GCM V2

    • Optimize your CMP. If you have dedicated Usercentrics Customer Success Executive, talk to them about your options regarding for your individual setup. We also recommend reading our opt-in optimization whitepaper for guidance.

• When using Advanced Google Consent Mode (GCM) (“advanced implementation” in the screenshot below from Google’s documentation), the drop in data in GA4 can also be related to non-consenting end users. So the previous improvement suggestion about CMP optimization is applicable here, too.

  If you fulfill Google’s prerequisites for behavioral modeling with to Google Consent Mode (see screenshot below), you should also see improvement with that over time.

How to reverse the GA4 drop in data with Advanced Google Consent Mode

• Meet as many of the prerequisites listed above as possible. For example, driving more traffic to your website(s) can help to meet the thresholds that are required for behavioral modeling.

  • Use the data you do have from consenting end users to estimate overall numbers, either long-term — if you cannot meet the above prerequisites from Google — or until behavioral modeling from GCM kicks in for you.

Wrapping up

Depending on legal requirements and requirements from Google that you may need to meet, using a Google-certified CMP like Usercentrics CMP is most likely your best bet. Our CMP comes with Google Consent Mode v2 integrated, so we’ve got you covered!

A decrease in GA4 data may occur, but there are ways to improve that and potentially even surpass what you’re used to thanks to the option of Advanced Google Consent Mode, as outlined above.

Your company may need to obtain end-user consent for the collection and use of customers' or users' personal data. Or you may need to ensure that users can opt out of data processing for various purposes. Data privacy regulations and business requirements for privacy and consent continue to expand globally. Google might require you to use Google Consent Mode, and different jurisdictions might require consent due to their legal frameworks on data privacy. With the Usercentrics CMP, you can meet these requirements reliably while demonstrating respect for data privacy and user rights to build trust.