Direct answer: what is Consent Mode v2?
Consent Mode v2 is the system Google Analytics 4 and Google Ads use to adjust their measurement based on the cookie consent a visitor gives via your cookie banner. Since March 2024 it has been mandatory for anyone using Google Ads remarketing or personalised advertising for visitors in the EEA. Without a correct implementation, conversion tracking and remarketing stop working reliably.
Why mandatory since 2024
The requirement follows from a combination of EU legislation: GDPR requires explicit consent for non-essential cookies, and the Digital Markets Act (DMA) imposes additional requirements on large platforms like Google regarding how they may combine personal data of EEA users across services.
In response, Google built Consent Mode as a technical mechanism: instead of blocking tags entirely without consent, they send an explicit signal (granted or denied) so Google's systems know exactly what may and may not be measured.
Basic vs advanced consent mode
There are two implementation modes, with a fundamental difference in how tags behave before a visitor makes a choice.
| Feature | Basic consent mode | Advanced consent mode |
|---|---|---|
| Tags load without consent | No — only after visitor choice | Yes, but without setting cookies |
| Data without consent | No data | Cookieless pings with anonymised signals |
| Modeled conversions | More limited | More extensive — GA4 fills gaps statistically |
| Implementation complexity | Simpler | Requires proper CMP integration |
Impact on GA4 and Google Ads measurement
Without a correct implementation you lose conversion attribution for every visitor who declines consent, your remarketing lists shrink and your GA4 reports show an incomplete or skewed picture. Modeled conversions statistically fill part of that gap, but remain estimates, not exact counts.
Practical implementation via a CMP
Most businesses implement Consent Mode via a Consent Management Platform (CMP) like Cookiebot, Iubenda or Osano, or via a custom solution. The flow is the same in every case: the CMP loads first, sets the default consent state to 'denied' before GA4 or Ads tags load, and pushes a consent update once the visitor makes a choice.
Example: the dataLayer calls
Two gtag calls form the core of every implementation. First, on page load, you set the default state to 'denied' for every category: gtag('consent', 'default', { ad_storage: 'denied', ad_user_data: 'denied', ad_personalization: 'denied', analytics_storage: 'denied' }).
Once the visitor grants consent via your cookie banner, you push an update: gtag('consent', 'update', { ad_storage: 'granted', ad_user_data: 'granted', ad_personalization: 'granted', analytics_storage: 'granted' }). Only the categories the visitor actually allows get set to 'granted'.
What happens if you don't implement it?
Google Ads can no longer correctly attribute conversions to campaigns for visitors in the EEA, your remarketing lists shrink structurally, and GA4 reports become unreliable for decision-making. In some cases, Google Ads accounts show explicit warnings about missing consent signals, which can limit campaign performance over time.
Our own consent flow on organiqgrow.nl
On organiqgrow.nl we use an og_consent cookie that records the visitor's choice and feeds it into our Consent Mode implementation. Only after explicit consent do analytics and advertising tags load with full functionality; without consent, only cookieless, anonymised measurement stays active. This approach keeps our own data clean and compliant, and it's the same standard we implement for clients.
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