What is consent mode?
According to Google, consent mode adjusts the behaviour of tags based on users’ consent choices. It is not a cookie banner but the link between the banner and Google’s services: the consent management platform asks for consent, and consent mode passes it on to Google Analytics, Google Ads and the other Google tags.
Without this link, tags do not know whether they may set cookies. Either they are blocked completely, or they run without valid consent. Both are bad: in the first case data is missing, in the second there is a risk of a data protection breach.
The signals of Consent Mode v2
Consent mode supports several consent types. Four are decisive for analytics and advertising:
- analytics_storage: allows cookies for web analytics, for example from Google Analytics.
- ad_storage: allows cookies for advertising, for example for conversion measurement in Google Ads.
- ad_user_data: allows user data to be sent to Google for advertising purposes. New in version 2.
- ad_personalization: allows personalised advertising. New in version 2.
For personalised advertising, both ad_user_data and ad_personalization must be granted. If ad_personalization is missing, remarketing lists in Google Ads, among others, no longer receive data.
Basic or advanced: two ways to implement it
- Basic: Google tags only load once the visitor has made a choice in the banner. No data is sent to Google before that. If the visitor declines, it stays that way.
- Advanced: the tags load immediately, but with the default set to “denied”. Without consent they send measurements without cookies to Google, known as cookieless pings. On this basis, Google can model missing conversions and visits.
According to Google, basic mode uses general models, while advanced mode uses models tailored to the individual advertiser’s data. Which option is right is also a legal question: you should clarify with your data protection officer or legal adviser whether transmission without consent is permissible.
Why Google requires consent signals
Since March 2024, Google has required anyone who measures users in the European Economic Area with Google tags or uses audiences and personalised ads to pass their consent on to Google: via Consent Mode v2 or via the Transparency and Consent Framework (TCF) of a certified consent management platform. Google’s EU user consent policy, which requires valid consent in the first place, also covers the UK and Switzerland. The background is Google’s consent policy in connection with the EU Digital Markets Act.
If the two new signals are missing, data is missing: remarketing lists stop growing and bidding strategies in Google Ads work with fewer conversions. Consent mode does not replace consent. It only ensures that Google knows and respects the visitor’s decision.
Setting up and checking consent mode
- Choose a consent management platform: common providers support Consent Mode v2 and send the signals themselves.
- Set defaults: before any choice, all signals that require consent are set to “denied”.
- Connect the tags: in Google Tag Manager, every tag must respect consent, including third-party tags without consent mode. A cookie and tracking switch handles this.
- Test: use Tag Manager’s preview mode and the browser’s developer tools to check that the right signals are sent before and after consent.
- Monitor: in Google Ads and Google Analytics, the diagnostics show whether consent mode is recognised correctly.
If you also use server-side tracking, consent must be passed on there too.
Would you like Consent Mode v2 set up properly or checked? Then get in touch with us or read more about our consent management!
