Google Consent Mode v2 - how it works

What is Consent Mode

A Google mechanism that controls how Google tags (GA4, Ads, Floodlight) behave depending on the user consent state. Instead of fully blocking, Consent Mode lets tags send cookieless pings - anonymous signals without identifiers.

Four consent types (v2)

analytics_storage (GA, Tag Manager), ad_storage (Google Ads, remarketing), ad_user_data (sending data to Google), ad_personalization (personalized ads). State: „granted" or „denied".

Defaults and updates

cl.js sets gtag('consent', 'default', {...denied}) BEFORE GA loads. When the user clicks „Accept", cl.js calls gtag('consent', 'update', {...granted}). GA then sends full data.

// Defaults (before GA, automatic via cl.js)
gtag('consent', 'default', {
  ad_storage: 'denied',
  ad_user_data: 'denied',
  ad_personalization: 'denied',
  analytics_storage: 'denied',
  wait_for_update: 500
})

// Update (after Accept, also via cl.js)
gtag('consent', 'update', {
  ad_storage: 'granted',
  ad_user_data: 'granted',
  ad_personalization: 'granted',
  analytics_storage: 'granted'
})

Why required since March 2024

Google requires Consent Mode v2 for EEA (EU + Norway, Iceland, Liechtenstein, Switzerland, UK). Without it: Google Ads stops serving ads to users from these countries, GA shows significantly lower numbers (modeling kicks in only with v2).