What is Google Consent Mode?

Google Consent Mode is a feature designed to help website owners comply with privacy regulations such as GDPR in Europe and CCPA in California, while allowing them to collect important data about user usage. their site.

Google Consent Mode does not play the same role as Consent Management Platforms (CMPs), and therefore does not replace them.
Google Consent Mode allows websites to change the behavior of their Google tags based on user consent for tracking .

This means that site owners can configure their Google tags to perform differently depending on whether or not the user has given consent for tracking.
We recommend that you integrate Consent Mode v2 via the native integrations available in the main Consent Manager Platform (CMP) on the market.



The new features brought by Consent Mode v2


Consent Mode version 2 (GCM v2) represents a significant update over the previous version, introducing new features to better align with European privacy and consumer protection laws, such as as the General Data Protection Regulation (GDPR) and the Digital Markets Act (DMA).

There are two implementation modes:

Basic Mode: Google solution tags remain blocked in the event of non-consent. Only consented traffic is analyzed and feeds Google solutions.

Advanced Mode: Advanced mode allows Google tags to be triggered even when the user does not consent. In the event of non-consent, Google uses conversion modeling to estimate user actions on the site , which helps close conversion gaps and ensure that data and insights remain complete and accurate, making it easier to take. informed decisions based on user interactions with the website.


The decision to choose between advanced mode and basic mode must be taken under the recommendations of your Legal team and your Data Protection Officer (DPO).
Technically, advanced mode collects pings from opt-out users, which helps prevent Google from needing to access browser storage.

This way, cookies containing personal data (such as online identifiers) will not be accessible by Google services, and ephemeral and random identifiers are used instead.
If advanced mode seems the most suitable for continuing to feed Google solutions with as much data as possible and thus preserving the performance of Google Ads acquisition campaigns, this system is currently neither validated nor invalidated by the CNIL.

It should be noted that even in advanced mode, Google will collect data through its pings such as:

Functional information such as timestamp, user agent and referrer.

General/non-personal information: a number generated randomly on each new page load, a boolean reflecting the consent status, an indication whether the current page or a page previously visited in the user's session on the site contained click-through information in the URL (like GCLID/DCLID) .

Other advertiser-specified variables: These are passed as standard (e.g. order_id, conversion value).
If you want to implement Advanced mode and add a layer of security, this information can be proxyfied (by hiding the last octets of the IP for example).



Consent Mode v2 in detail


GCM v2 introduces two new parameters to Google's consent mode API: `ad_user_data` and `ad_personalization` .

These settings allow websites to collect more granular consent, that is, consent where the user clearly understands each specific piece of data collected and its use.

The `ad_user_data` parameter sets consent for sending user data to Google for advertising purposes, while `ad_personalization` sets consent for personalized advertising.

These parameters are added to the existing `analytics_storage` and `ad_storage` parameters for finer management of user consent.


Unlike 'ad_storage' and 'analytics_storage' , these flags have no functional impact on the behavior of tags on the site itself.

These are additional parameters sent with pings to Google services, designed to instruct those services on how user data may be used for advertising.

So, while 'ad_storage' and 'analytics_storage' will qualify the data upstream of collection (because they control which identifiers are sent with the pings), 'ad_user_data' and 'ad_personalization' are instructions that intervene downstream.

Consent Mode has additional, more advanced settings like 'ads_data_redaction' , which prevents any third-party click IDs or cookie decorations from passing through ad feeds.

Additionally, there are settings like 'allow_ad_personalization_signals' that also govern the type of data Google ad services can access

If there is a conflict between these settings and the Consent Mode, the "stricter" setting prevails in favor of data protection.

Businesses using Google services in the European Union (EU) or European Economic Area (EEA) must implement GCM v2 by March 2024 to continue access to ad personalization, remarketing, and measurement features.
If GCM v2 is not implemented by this deadline, Google services such as Google Analytics 4 and Google Ads will not capture any data about new users from the EU or EEA, which could seriously impact the effectiveness of companies’ advertising strategies.