Definition:
Google Consent Mode is a mechanism that communicates a person’s consent choices to Google tags. Compatible products use those signals to adjust how they handle storage, advertising data and personalisation.
It is not a cookie banner, a consent platform or a legal basis. A website or app must obtain the choice through a custom solution or a CMP (Consent Management Platform) and then send the corresponding state. Consent Mode does not guarantee legal compliance by itself.
Table of contents
How Google Consent Mode works
An implementation starts with a default state for each consent type. This state must be established before affected tags use storage or send data. When a person accepts, rejects or changes their preferences, the CMP or custom solution communicates an update.
Compatible tags adjust their behaviour according to those values. They include the Google tag, Google Analytics, Google Ads, Floodlight and Conversion Linker. Third-party tags do not automatically acquire the same behaviour: each provider needs its own rules and tests.
There are two common configuration routes: gtag.js code or Google Tag Manager. GTM helps organise execution and consent checks, but it does not replace the CMP or decide which choice should be requested.
Consent types
The state is expressed as granted or denied for independent signals. The four most relevant signals for Google’s measurement and advertising products are:
analytics_storage: controls storage related to analytics, such as certain measurement cookies.ad_storage: controls cookies or identifiers associated with advertising.ad_user_data: indicates whether consent exists to send user data to Google for advertising purposes.ad_personalization: indicates whether consent exists to use data for personalised advertising.
Consent Mode also defines functionality_storage, personalization_storage and security_storage for functional, personalisation and security storage. The technical map should not group all signals for convenience when the interface offers separate choices: it needs to reflect the purposes shown to the user.
Basic and advanced mode
Consent Mode supports two implementation approaches. The distinction describes what happens before and after the choice; it does not represent two levels of compliance:
- Basic mode: Google tags remain blocked until the relevant consent is granted. If consent is not granted, those tags do not send data or the consent state to Google.
- Advanced mode: compatible tags can load with denied default states. While consent remains denied, they may send cookieless measurements and later adjust their behaviour if the state changes.
A cookieless measurement is still a data communication. It may include the consent state and general request information such as a timestamp, user agent, referrer or indications of ad-click parameters. Therefore, without cookies does not automatically mean anonymous, free of processing or legally permitted in every context.
Measurement and modelling
In advanced mode, cookieless signals may contribute to modelling results in Google Analytics and Google Ads when each product’s requirements are met. The calculation attempts to estimate some gaps between observed data, but it does not reconstruct an identity or confirm which person completed a conversion.
Not every property reaches the required thresholds, and modelled results do not have to match a CRM. Variable limits depend on volume, implementation, received choices and product rules. Consent Mode does not guarantee recovery of every declined conversion or a specific improvement in advertising performance.
Keep two controls separate: consent state and event quality. A correctly communicated choice does not fix inconsistent names, duplicates, incomplete parameters or attribution errors.
Implementation and limitations
A verifiable implementation must coordinate consent, tags and destinations. At a minimum, it requires these controls:
- Technical inventory: locate tags, plugins, scripts, forms, subdomains and server-side measurement flows.
- Signal map: relate every purpose shown in the CMP to the states that are actually sent.
- Loading order: establish defaults before measurement and update the choice without overwriting it.
- Complete tests: check no interaction, rejection, acceptance, partial selection, withdrawal and navigation between pages.
- Maintenance: repeat tests when the banner, container, templates or integrations change.
Complete validation should cover Tag Assistant, cookies, storage and network requests. Seeing a denied state in one interface does not prove that every tag respects it. The practical guide to Consent Mode v2 expands the configuration and testing process without changing the definitional purpose of this glossary entry.