Consent Mode

Written by Cobus van der Westhuizen, reviewed by Wynand van der Westhuizen, fact-checked by Lenata Oosthuizen. Last reviewed July 2026. Editorial policy.

What Is Consent Mode?

Consent Mode is a configuration layer built into Google Tag Manager and the Google tag that tells Google's measurement products how to behave when a user has not accepted cookies.

Rather than blocking all data collection when someone clicks "Decline" on a cookie banner, Consent Mode sends cookieless pings to Google's servers.

Google then uses machine learning models to fill the gaps and estimate the conversions that were not directly observed, a process Google calls conversion modelling.

There are four primary consent signals that Consent Mode v2 controls. The first two, analytics_storage and ad_storage, have been available since the original release.

Version 2 added ad_user_data, which governs whether user data is sent to Google for advertising purposes, and ad_personalisation, which controls whether data is used to personalise ads for the individual.

Each signal can be set to "granted" or "denied" independently, giving advertisers precise control over what data flows where.

Google required all advertisers using Google Ads conversion tracking or remarketing to implement Consent Mode v2 by March 2024 for users in the European Economic Area.

While South Africa is not formally subject to GDPR, the Protection of Personal Information Act (POPIA) imposes similar obligations around obtaining informed consent before processing personal data.

South African businesses that serve users in Europe or that operate on international e-commerce platforms have a direct legal obligation. Beyond compliance, any South African business that values accurate ad measurement and a clean data set should treat Consent Mode as standard infrastructure.

Implementing Consent Mode requires a consent management platform (CMP) that integrates with Google Tag Manager. When a visitor lands on your site, the CMP reads their stored consent preference or presents a banner.

The consent state is passed to GTM as variables, which update the Consent Mode signals before any marketing tags fire. This ordering is critical. If tags fire before the consent state is set, the Consent Mode implementation is broken and non-compliant.

Consent Mode In Practice

Consider a Johannesburg-based fashion retailer running Google Ads with Smart Bidding. Without Consent Mode, every visitor who declines cookies becomes invisible to Google's bidding algorithm.

The algorithm incorrectly assumes these visits generated zero conversions and starts misallocating budget away from audiences that actually convert at high rates.

With Consent Mode active, Google's modelling estimates the conversions from the declined segment and feeds them back into the Smart Bidding system, keeping it calibrated.

For a Pretoria-based B2B software company running remarketing campaigns, Consent Mode also protects the brand. Users who decline cookies are not cookied for remarketing lists, ensuring the company does not inadvertently retarget people who explicitly opted out.

This reduces ad fatigue complaints and keeps the brand reputation clean. At the same time, the analytics data remains usable because modelled data fills the measurement gap.

The result is a setup that respects user choice and still gives the marketing team the data they need to justify the monthly Google Ads budget.

What Consent Mode is

Consent Mode is a Google feature that lets a website adjust how Google's tags and services (such as Google Analytics and Google Ads tracking) behave based on the consent choices a visitor has made regarding cookies and data collection, so that tracking respects the user's consent preferences. When a visitor is presented with a cookie or consent banner and makes choices (accepting or declining various categories of cookies and data use), Consent Mode communicates those choices to Google's tags, which then adjust their behaviour accordingly, for example, collecting data fully where consent is given, and limiting or not collecting certain data where consent is withheld. This helps a business use Google's analytics and advertising tools in a way that respects user consent and aligns with privacy regulations that require consent for certain tracking. Consent Mode works alongside a consent management setup (a cookie banner or consent platform that captures the user's choices) by taking those choices and applying them to how Google's tags operate. A notable feature is that, where consent is declined, Consent Mode can still provide Google with certain privacy-preserving, aggregated or modelled signals (rather than full data), allowing some measurement while respecting the lack of consent, depending on the configuration. Understanding Consent Mode matters because privacy regulations increasingly require respecting user consent for tracking, and Consent Mode is Google's mechanism for making its analytics and advertising tags behave in line with those consent choices, so for businesses using Google's tools and needing to handle consent properly, knowing what Consent Mode is, and that it adjusts Google's tracking based on user consent, is relevant to using those tools compliantly and respecting user privacy.

Implementing Consent Mode and versions

Implementing Consent Mode involves connecting a consent management setup (that captures users' cookie and data-use choices, typically via a cookie banner or consent platform) with Google's tags, so that the users' consent choices are passed to and respected by Google Analytics, Google Ads and other Google tags. In practice, this usually means having a consent banner or consent management platform that records the user's choices, and configuring Consent Mode (often through Google Tag Manager or the tag setup) so those choices control how Google's tags behave, for example, adjusting or withholding data collection where consent is not given. Many consent management platforms and Google Tag Manager provide integrations that make setting up Consent Mode more straightforward. On versions: Consent Mode has evolved, with a version 2 (Consent Mode v2) introducing additional consent signals and requirements. The key difference is that Consent Mode v2 added new consent parameters (relating to whether user data may be used for advertising and personalisation purposes) beyond the original signals, providing more granular consent information, and Google made Consent Mode v2 a requirement for certain uses of its advertising and personalisation features in regions with applicable privacy laws (notably the European Economic Area), so businesses using Google's advertising features for those audiences needed to adopt v2 to continue using certain features. In short, v2 extended the consent signals (particularly around advertising/personalisation consent) and became required for certain Google advertising features in applicable regions, whereas v1 had the original, narrower set of signals. On whether it is required: Consent Mode's necessity depends on the privacy laws applicable to a website's audience and the Google features it uses, it is particularly relevant (and, in v2 form, required for certain Google advertising features) for audiences in regions with strict consent requirements like the EEA, while its applicability elsewhere depends on the local privacy regime and the business's obligations. For a South African business, whether Consent Mode is needed depends on its audience and legal obligations: if it serves audiences in regions with strict consent laws (like the EEA) and uses Google's advertising and analytics tools, Consent Mode (v2) may be required for those features; and while South Africa's own privacy law (POPIA) governs personal data handling, the specific requirement for Consent Mode depends on the applicable regulations and Google's requirements for the features used. The practical guidance is to implement proper consent handling (a consent banner or platform) and, where the business uses Google's analytics and advertising tools and serves audiences whose privacy laws require it, to configure Consent Mode (v2) so Google's tags respect users' consent, ensuring the business uses these tools in a privacy-compliant, consent-respecting way appropriate to its audience and obligations.

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