By Marc Alexander

If you run Google Ads to people in the EEA, Consent Mode v2 isn't optional. The real decision is which version: basic or advanced.

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.

  • For: GA4 and Google Ads can model what's missing from your own data, so reports and bidding lose less.
  • Against: something is still sent to Google before the visitor has chosen. Some lawyers and regulators take the view that even that needs consent under the ePrivacy rules.

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. A smaller site may take on the legal question of advanced mode and still get no modelled data back. For those sites, basic mode often makes more sense.

How to choose.

  1. Ask your DPO or lawyer first. Whether cookieless pings before consent are acceptable is their call, and the answer differs between organisations and countries.
  2. Check your volumes. If you're well below Google's thresholds, advanced mode brings the risk without the benefit.
  3. Consider your ad spend. The more you rely on Google Ads bidding in Europe, the more modelled conversions are worth.
  4. Choose per region if you need to. You can run advanced mode where it's accepted and basic elsewhere, 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 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.