Google Consent Mode
What is Google Consent Mode?
Google Consent Mode is the way a site tells Google’s advertising and measurement tags whether a visitor agreed to cookies, and to what. The banner collects the consent; Consent Mode carries the answer and decides what each tag may store. When someone refuses, the tags either never load or run without identifiers, so nothing is tied to a person.
Example
A shop with 10,000 visitors a month. The banner asks, six in ten accept marketing cookies. With no consent signal in place, Google’s tag simply says nothing about the other 4,000 people. They are missing from analytics and from the ad reports, and the channel looks 40% weaker than it is.
With Consent Mode there are two ways to run it. In basic mode the tags do not load at all until there is an answer: refusals produce no data, but nothing is stored without permission. In advanced mode the tag loads immediately and, on a refusal, sends a signal carrying no identifiers — no cookie, no advertising profile. Google uses those signals to estimate what is missing, provided the volume is there. Sixty measured orders at €80 can come back as roughly ninety in the report: around €7,200 rather than the €4,800 the raw count shows.
Why it matters for a business
Since March 2024 Google has required the two extra version 2 signals: whether the data may be used for advertising, and whether the advertising may be personalised. Without them, remarketing audiences for the European Economic Area stop filling and parts of Google Ads switch themselves off. An empty audience is a stopped campaign, which makes this a commercial matter rather than a technical one.
The other half is legal. Consent Mode is not consent. The cookie rules still require a yes before a tracking file is written to someone’s device, and the banner still has to make refusing as easy as accepting, and withdrawing possible later. Half-configured, the setup delivers the worst of both: lost measurement and cookies set without a basis.
What to ask
- Is the site on basic or advanced mode, and what decided it?
- Does a refusal stop every tag — Google, Meta, the chat widget, the behaviour tools — or only Google’s?
- How was it verified that the signals actually fire? Is there a test record rather than an assurance?
- Can a visitor withdraw consent later, and is that decision remembered on the next visit?
We set it up alongside the Google Ads work, because otherwise the conversion report and the cookie banner contradict each other.