GuideMeasurement and attribution
Consent Mode
Definition
The mechanism that governs what Google’s tags may measure when a visitor declines cookies, and that models the conversions lost as a result. It sits at the join between your cookie banner and your reported numbers.
How it works
When a visitor answers the banner, the consent state is passed to Google’s tags. After a decline, the tags either stay silent or, in the advanced implementation, send cookieless pings carrying no identifier. From those pings and the behaviour of consenting visitors, Google models the conversions it could no longer observe and adds them to the reports. The number you read in GA4 or Google Ads is therefore a blend of observed and modelled conversions, presented in one column.
What to watch for
Open your site in a private browser, decline everything, and watch what loads: tags that fire anyway are a legal exposure, and no measurement question matters until that is fixed. Then take one month and count orders twice, once in the shop system and once in analytics. A gap explained by your decline rate is the system working as designed; a gap beyond it is the thing to chase. An analytics count that matches the shop exactly while a visible share of visitors decline deserves suspicion too, because something is filling the gap, and it matters whether that is modelling or tags firing without consent.
The question you ask
“What share of the conversions in this report is modelled?”