Consent Mode v2 is Google’s mechanism for letting tags fire in privacy-respecting ways when consent isn’t granted. Tags receive consent state (granted / denied / unset) via gtag('consent', 'default', ...) and either fire fully, ping in cookieless mode (ad_storage: denied means anonymized pings), or stay silent. Required since March 2024 if you want Google Ads conversions to work for EU traffic without explicit consent. v2 added two new parameters (ad_user_data and ad_personalization) on top of v1. If you’re keeping GA4 in parallel during a migration to a privacy-first tool, you must implement v2.
Consent Mode v2
Google's framework for adjusting tag behavior based on user consent state — required as of March 2024.