Consent Mode is a component of a website or application’s data collection architecture which will “translate” the consent preference of a consumer, as indicated via a Consent Management Platform (CMP), into a signal readable by Google tags (e.g Google Analytics 4 and Google Ads) loading on the same page. Based upon the consent signal indicated by Consent Mode, Google tags will automatically modify their behavior according to the consent signals provided. In essence, implementation of Consent Mode provides additional parameters sent with requests to Google that will enable certain functionality. Moreover, this approach ensures user requests for autonomy are respected throughout the Google ecosystem.
Consent Mode is not a CMP and it does not replace the need for a CMP. Rather, consent Mode works in tandem with a CMP to provide the necessary consent signals to Google for Google’s platforms to process provided data. Consent Mode is just a feature (a Google Tag Manager (GTM) tag and suite of variables) that is enabled by running some code on the site via a tag before Google tags fire, and making updates when a user modifies their tracking preferences. Think of this functionality as foundational and now a requisite to the implementation of all Google tags.
As of March 2024, Consent Mode signals must be present for data collected via Google tags (GA, Floodlights, Ads tags) to be used for targeting use cases in Google platforms. The requirement is 100% for data from visitors from the European Economic Area (EEA); it is unclear (but recommended) if this requirement will apply to all global properties.
Types of Google Consent Mode Implementations
Two types of Google Consent Mode implementations currently exist:
- Basic = Block Google Tags when a user rejects cookies
- Advanced = Allow Google Tags to free-fire regardless of user consent
Basic Consent Mode introduces Consent Mode; however, Google’s tags are prevented from loading and collecting data until user consent is granted. In other words, data is collected only if the user grants consent. For instances where users decline any non-essential tracking, no data is collected.
Advanced Consent Mode implementations differ in that data is collected from users when they grant consent and when they deny consent. In other words, Google’s tags load and collect data regardless of user consent. For instances where a user has not given consent, data is collected; however, all user activity data has undergone anonymization to follow the user preference of anonymity.
Basic Consent Mode meets Google’s requirements for data privacy standards, while Advanced Consent Mode provides additional benefits. Data modeling is a value provided by the implementation of Consent Mode; both “behavioral” and “conversion” modeling can be obtained. Note, however, that with the implementation of Basic Consent Mode, full benefits of Consent Mode are not achieved—only conversion modeling will be enabled. Advanced Consent Mode is required for behavior modeling, where modeling data is introduced to a GA4 property that fills in the gaps for the missing observed data when users decline consent. As a prerequisite for behavior modeling, data thresholds must be met to provide this element of functionality.
Google Consent Mode Version 2
Google has recently introduced an updated version of Consent Mode to ensure compliance, respecting user consent. This includes both upstream (browser network calls) as well as downstream (backend Google data processing) With this new version, Google still supports both the Advance and Basic configurations of Consent Mode.
A primary enhancement to Consent Mode V2 is the introduction of two new consent signals:
- ‘ad_user_data’ determines whether the data may be used for advertising purposes
- ‘ad_personalization’ determines the usability specifically for personalized advertising
Consent Mode allows you to satisfy Google’s requirement “to pass through end-user consent choices to Google.” The Consent Mode V2 updates specifically signal user consent for Google to process data for advertising when such consent is granted.
Basic Google Consent Mode gcs and gcd Parameters
When tags are triggered by following the Consent Management Platform (CMP) logic, the parameters will only be present when the tags fire (i.e. user has given consent)
For example and for purposes of illustration, when a user does consent for Analytics (0002)
gcs = G111
gcd = 13t3t3t3t6
Advanced Google Consent Mode gcs and gcd Parameters
And when Advance Consent Mode has been implemented, because tags are firing regardless of user consent, not only will the parameters always be present but the parameters will reflect the state of user consent.
For example and for purposes of illustration, when a user does not consent for Analytics (0002)
gcs = G100
gcd = 11p1p1p1p5
For example and for purposes of illustration, when a user does consent for Analytics (0002)
gcs = G111
gcd = 13t3t3t3t6
Options for Google Consent Mode Testing
Several options exist for testing. Some are easier and more convenient than others. Browser network payload data will reveal the presence of the gcs and gcd parameters. However, there are easier ways to test the functionality of Google Consent Mode, one of which is a Chrome extension developed by InfoTrust. Designed to expedite the testing process, the extension will show the current state of Consent Mode. Important to note that it won’t give an explicit recommendation as to “good” or “not good” as that will be dependent upon the organization, their compliance policies, and the consent state of the user. In summary, testing ultimately requires comparing the extensions output with user consent as configured within the CMP.
