By Marc Alexander

Two exploded diagrams side by side. In basic Consent Mode, the banner is a cookie tin lid where the visitor clicks Reject all, the tags wait on a rack behind a shut padlock, and Google's receiving dish stays empty. In advanced Consent Mode, after the same choice the padlock is open, the tags load in a restricted state, and cookieless pings still land on Google's dish.
Tap the diagram to open it full size.

Since March 2024, Google has required advertisers to send consent signals for visitors in the European Economic Area. Without them, Google Ads loses remarketing audiences and some conversion measurement for that traffic. Consent Mode v2 is how the signals get there.

Consent Mode is a set of signals your site passes to Google's tags: whether the visitor agreed to analytics storage, advertising storage, their data being sent to Google for advertising, and personalised ads. The last two, ad_user_data and ad_personalization, are what the "v2" added.

Google's tags then change what they do. With consent, they work as normal. Without it, they either stay silent or send limited signals, depending on which version you've set up.

Basic: nothing until they agree.

In basic Consent Mode, Google's tags don't load at all until the visitor makes a choice. If they agree, the tags fire with consent granted. If they refuse, Google receives nothing from that visit.

  • For: the simplest to explain. No data of any kind goes to Google from a visitor who refused.
  • Against: Google has nothing to model from, so conversions and users from visitors who refused are simply missing. Google applies a general model instead of one built on your site.

Advanced: limited signals before they agree.

In advanced Consent Mode, Google's tags load straight away with consent denied by default. Until the visitor agrees, they send cookieless pings: no cookies are set or read, and the pings carry no identifier that links them to a person over time. That doesn't make it compliant: Advanced Consent Mode v2 isn't GDPR compliant, for the reason below.

  • For: GA4 and Google Ads can model what's missing from your own data, so reports and bidding lose less
  • Against: data still goes to Google before the visitor has chosen, or after they've refused: each ping carries the page and reaches Google with the visitor's IP address. That needs consent, so Advanced Consent Mode v2 isn't GDPR compliant.

Modelling needs volume.

Advanced mode only pays off if GA4 can build a model. Google's published thresholds for behavioural modelling in GA4 are:

  • at least 1,000 events a day with analytics storage denied, for at least 7 days
  • at least 1,000 users a day sending events with analytics storage granted, for at least 7 of the previous 28 days

Meeting them doesn't guarantee a model: Google applies further checks of its own. So the one benefit of advanced mode often never arrives, while the compliance problem always does.

What Marc recommends.

  1. Use basic for UK and EEA visitors. Nothing goes to Google until the visitor agrees, which is what consent means.
  2. Accept the gap. Conversions from people who refused are missing, and Google applies a general model instead of one built on your site. That's the cost of asking properly.
  3. Make agreeing a real choice. A clear banner, with Reject as easy as Accept, means the people who agree have done so properly.
  4. Set defaults by region. Visitors elsewhere can have different defaults, with region-specific consent settings.

The mistakes that matter more than the choice.

Most broken setups fail for reasons that have nothing to do with basic or advanced:

  • the default isn't set before Google's tags load, so the first hits go out with no consent state at all
  • the banner updates analytics_storage and ad_storage, but not the two v2 signals
  • "advanced" is switched on by accident because the tags load before the banner, rather than by decision
  • non-Google tags, which Consent Mode doesn't control, run regardless

Test every state as an EEA visitor: before a choice, after accepting, after rejecting, and after changing your mind. The guide to testing Consent Mode v2 shows what to look for in each.

Marc Alexander, a Tag Manager specialist, sets up Consent Mode v2 for European businesses, wired to your banner and tested in each state. The GA4 mini audit checks what yours does today.

Sources.

Checked on 31 October 2026.