Glossary
Consent mode
A mechanism that tells tags whether a visitor consented, so they adjust behaviour instead of firing or not firing. Consent is the permission; consent mode is the plumbing.
Also called: consent signalling
Before consent signalling, the choice was binary: a tag either fired or it did not. Consent mode adds a third state — the tag fires, but it is told what it is allowed to do, and it degrades accordingly. Without consent it may send a request carrying no identifiers, which lets the platform count something without storing anything on the visitor’s device.
The distinction that causes most of the confusion: consent is the legal permission you obtained from the visitor. Consent mode is the technical mechanism that communicates that permission to your tags. Implementing the mechanism does not obtain the permission, and a correctly configured consent mode sitting behind a banner that nobody meaningfully agreed to is a well-plumbed compliance problem.
What it means for your reporting. Consented and non-consented visitors are measured differently, so the gap does not appear as missing rows. It appears as modeled conversions filling in the space, which means your totals combine observation and estimation in a proportion that shifts with your consent rate. A banner redesign can move reported conversions without a single thing changing about the business.
Two practical points. Consent rates vary enormously by region and by how the banner is built, so cross-market comparisons are usually comparing banner designs. And moving tags server-side does not change any of this — it changes who sends the request, never whether you were permitted to.
Do not confuse with
Close enough to get mixed up, different enough that the mix-up costs something.
- Cookie window How long a tracking cookie stays valid after it is set. Often confused with the attribution window, which is a reporting rule rather than a storage limit.
- Server-side tagging Sending marketing and analytics events from your own server instead of from the visitor's browser, so a request the browser might block is made somewhere it cannot be.
- Tracking prevention Browser features that limit how long identifiers survive and which requests are allowed, applied by default to everyone. Separate from consent, and not something the visitor opted into.