Consent Mode v2.

Consent Mode connects a website's cookie banner to the Google tags. Instead of simply blocking or loading tags, the consent management tool sends signals and the tags behave accordingly. The original version mainly knew two signals: ad_storage for advertising cookies and analytics_storage for analytics cookies. Version 2 added two more: ad_user_data controls whether user data may be sent to Google for advertising purposes, and ad_personalization whether it may be used for personalised advertising such as retargeting.

Google distinguishes two implementation types. In Basic mode, Google tags only load once consent has been given; without consent nothing is sent. In Advanced mode the tags load immediately but, without consent, send only cookieless signals without identifiers. Google uses these to model missing conversions. Which variant fits is a legal and strategic trade-off: Advanced produces more complete reports, Basic transmits nothing before consent.

Since March 2024 Google has required Consent Mode v2 for visitors from the European Economic Area. Without the signals, features such as remarketing lists, personalised ads and parts of conversion measurement are no longer available for those users. Swiss websites almost always have visitors from the EU as well and are therefore affected in practice. Which requirements Google applies to users in Switzerland should be checked in Google's current policies, in addition to the Swiss Data Protection Act.

Technically, Consent Mode is quickly activated; implemented cleanly, less often. Common mistakes: default values are set too late, so tags fire before the banner appears; the banner sends only the old two signals; after a refusal values remain at 'granted'. You can check this in Google Tag Manager preview mode and in the Google Ads diagnostics. Getting this right lays the foundation for all further conversion tracking.