Consent Mode v2, explained without the marketing
Since 2024 Google requires websites to pass the consent decision on to its services. What is actually transmitted, and what "modelling" means, tends to get lost in the marketing copy.
Consent Mode is not a consent tool. It is an interface through which a banner tells Google's services what the visitor decided. Obtaining the decision remains the banner's job – Consent Mode only ensures the decision arrives at the other end.
The four signals and what they govern
The last two signals arrived with version 2. They were the reason for the wave of migrations in early 2024: without them Google stopped serving certain advertising features in the European Economic Area.
Basic and advanced – the essential difference
Two modes with very different consequences
What "modelling" means
When many people refuse, correspondingly many events are missing from the reports. Google fills that gap by calculation: the behaviour of the consenting group is used to estimate how the refusing group probably behaved.
The result is an extrapolation, not a measurement. For the question "is the campaign doing better than last week" that is usable. As the basis for a statement about individual events it is not – and in the reporting interfaces the difference is not always obvious at a glance.
- Modelling requires a minimum volume of data. Small sites often fail to reach the thresholds and therefore see no effect at all.
- The signals do not replace consent. They merely report whether it exists.
- A miswired banner reports "granted" permanently. This is verifiable in the network log from the parameters of the request.
For practice this yields a simple order: first decide whether the services should be used at all, then choose basic mode where legal certainty matters more than completeness of reporting – and in either case check that the signals really report what was clicked in the banner.