GA4 Consent Mode v2: Basic vs Advanced for Marketers

#01Basic vs advanced

#02Copyable defaults (gtag)

Place this before the Google tag loads. It denies everything by default and gives the consent banner 500 ms to update:

window.dataLayer = window.dataLayer || [];
function gtag(){dataLayer.push(arguments);}
gtag('consent', 'default', {
  'ad_storage': 'denied',
  'ad_user_data': 'denied',
  'ad_personalization': 'denied',
  'analytics_storage': 'denied',
  'wait_for_update': 500
});

When the visitor accepts analytics only, the banner calls:

gtag('consent', 'update', {
  'analytics_storage': 'granted'
});

Google's developer guide notes that consent mode does not save choices. Your banner must store the choice and call update again on later pages. In Tag Manager, use a consent mode template from your consent platform, or the setDefaultConsentState and updateConsentState APIs.

#03How do you check it works?

1. Open the site in Tag Assistant (tagassistant.google.com).
2. Check the Consent tab for the default state on first load and the updated state after your choice.
3. In GA4 DebugView (lesson 16), confirm events arrive only in the states your policy allows.

Our view: consent rates drive data quality more than any GA4 setting. A clear, honest banner usually earns more opt-ins than a dark pattern, and it is the right thing to do.

Consent also explains part of the gap between GA4 and your own logs, which lesson 14 covers.

Next: Thresholds, sampling and data quality. Or return to the GA4 for Marketers track.

#04Common questions

What are the consent types in consent mode v2? ad_storage, ad_user_data, ad_personalization and analytics_storage. Each can default to denied and be updated when the visitor chooses.

Does advanced consent mode send data without consent? In advanced mode, tags load before the choice and send cookieless pings when consent is denied. No Analytics cookies are set or read in that state. Check this with your legal team.

Which mode gives better modelling? Google says advanced mode enables improved modelling, with an advertiser-specific model rather than a general one.