Definition
Consent Mode is Google's mechanism for telling its tags whether a visitor has agreed to storage and to the use of their data for advertising, so the tags can change their behaviour accordingly. A consent banner sets a small set of named signals, the Google tag reads them, and measurement adjusts: with consent it behaves normally, and without it storage is withheld while limited cookieless information may still be sent depending on the implementation.
The signals a banner sets and what each one controls
- analytics_storage
- Whether analytics cookies may be written and read, which decides if a visit joins a measurable session
- ad_storage
- Whether advertising cookies may be used, which decides if a click can be tied to a later purchase
- ad_user_data
- Whether user data may be sent to Google for advertising purposes
- ad_personalization
- Whether the visitor's data may be used for personalised advertising and remarketing audiences
- Default state before a choice
- Set to denied for visitors in regions where prior consent is required, then updated the moment the banner is answered
- Basic implementation
- Google tags do not load at all until consent is granted, so denied visitors leave no signal behind
- Advanced implementation
- Tags load in a denied state and send cookieless signals without identifiers, which is what allows conversion modelling to run
An illustrative configuration. The exact signals a banner sets come from your consent platform, and which regions require a denied default comes from your legal advice rather than from a tag setting.
Why it matters
Consent Mode matters because it decides whether a store keeps any measurement at all for visitors who decline cookies. Without it, Google tags in regulated regions either fire when they should not, which is a compliance problem, or are blocked entirely, which leaves a hole in reporting and starves bidding of signal. With it, the visitor's choice is respected and the store keeps a usable picture through modelling. It is also a practical requirement for Google advertising features in the European Economic Area and the United Kingdom, where the consent signals have to be passed for audience and personalisation features to keep working.
Where it goes wrong
- Installing a banner that blocks scripts on its own without passing the consent signals, so Google tags see nothing and behave as though no framework exists
- Leaving the default state as granted for regions that require a choice first, which sets cookies before the visitor has answered
- Loading the consent platform after the Google tag, so the first pageview is measured before the default state has been applied
- Expecting modelled conversions to appear immediately: modelling depends on meeting data thresholds, and a store with modest traffic in the affected regions may see gaps rather than estimates
- Reading the drop in recorded conversions after implementation as lost sales, when the orders are still arriving and only the ability to observe some of them has changed
Questions about Consent Mode
What is the difference between basic and advanced Consent Mode?
In a basic setup the Google tags are prevented from loading until consent is granted, so a visitor who declines produces no data at all. In an advanced setup the tags load immediately in a denied state and send cookieless signals that carry no identifiers, which gives Google enough input to model the conversions it cannot observe. Advanced retains more reporting; basic keeps fewer requests on the page.
Does Consent Mode reduce reported conversions?
Usually yes at first, because conversions that were previously recorded without a proper consent signal are no longer counted the same way. Modelling recovers part of that where thresholds are met. The important thing is to mark the implementation date on your reporting so the step change is understood as a measurement change rather than a performance one.
How does a Shopify store implement Consent Mode?
Shopify provides a customer privacy and consent API that a banner app writes to, and the platform can pass those choices through to Google tags installed via the Google and YouTube channel. Stores running their own tag manager wire the same choices into the consent initialisation. Either way the banner is the source of the decision and the tag setup is the consumer of it.