What Google Consent Mode does

Consent Mode passes a visitor’s consent state to supported Google products and changes how their tags behave. Depending on the implementation and the user’s choice, Google tags may either remain blocked or send limited measurements without cookies. When consent is granted, supported tags can operate normally and use the storage or data-processing features covered by that consent.
Google provides two implementation approaches: Basic Consent Mode and Advanced Consent Mode. Both reduce observable data compared with unrestricted tracking, but they handle denied or not-yet-provided consent differently. Advanced Consent Mode can provide additional privacy-preserving signals that Google may use for conversion and behavioral modeling, subject to eligibility thresholds.
Consent settings are vendor-specific. Implementing Google Consent Mode does not automatically configure Microsoft Advertising, Meta, or other platforms. Each platform requires its own consent signals and tag behavior. For example, Microsoft UET Consent Mode must be configured separately, with consent defaults set appropriately for regions where prior consent is required.

A consent banner is still required

Consent Mode is not a consent banner or consent management platform. It receives the choices collected by your banner and makes those choices available to Google tags. The banner therefore needs to be implemented first. You can use a custom consent solution or a Consent Management Platform (CMP).
Google maintains a directory of CMP partners that support Google Consent Mode. Google Tag Manager is typically the most practical place to coordinate consent states and consent-aware tag firing, especially when several marketing and analytics tags are involved.

Basic Consent Mode

With Basic Consent Mode, Google tags are blocked before the visitor interacts with the consent banner. No information is sent to Google during this period—not even the default consent state.
If the visitor grants consent, the Google tags load and the Consent Mode API communicates consent in this sequence:
The configured default consent state is sent.
The visitor’s updated consent state is sent.
If the visitor denies consent, Google tags remain blocked and no data is transmitted. Because Google does not receive advertiser-specific signals for these users, Google Ads conversion modeling relies on a more general model and provides less detailed recovery than an eligible Advanced Consent Mode implementation.

Advanced Consent Mode

With Advanced Consent Mode, Google tags load when the website or app opens, before the visitor makes a choice. The implementation sets default consent states—commonly to denied where prior consent is required—and then updates those states after the visitor interacts with the banner.
The tag flow works as follows:
Google tags load and read the configured default consent states.
While the relevant storage consent is denied, supported tags do not read or write the associated cookies and may send measurements without cookies.
After the visitor makes a choice, the consent states are updated.
When consent is granted, supported tags can send full measurement data and use the permitted cookies or identifiers.
Because Advanced Consent Mode provides advertiser-specific signals even when storage consent is denied, it can support more detailed modeling than Basic Consent Mode. Modeling is not guaranteed: Google applies product-specific eligibility requirements and data thresholds.

What is sent when consent is denied?

When a visitor grants the relevant consent, supported tags function normally. When consent for storage is denied under Advanced Consent Mode, consent-aware Google tags do not use the corresponding cookies or device identifiers. Instead, they may send limited measurements without cookies to Google.
These requests can include the following signal types:

• Consent state pings, which communicate whether each consent type—such as ad_storage or analytics_storage—is granted or denied.
• Key event pings, which indicate that a key event occurred.
• Google Analytics pings, which may be sent when pages load and when events are recorded.

Depending on the product and configuration, the requests may contain:

• Functional request information, including a timestamp, browser user agent, and referrer.
• An indication that the current or a previous page contained an ad-click identifier, such as GCLID or DCLID.
• Boolean consent-state information.
• A random value generated on each page load.
• Information identifying the consent platform used by the website, such as a developer ID.

These signals help Google estimate measurement gaps without relying on the cookies covered by a denied storage-consent state. They are not equivalent to full tracking, and the exact tag behavior depends on the consent types, product settings, and any additional controls such as ads data redaction.

Implementation considerations

Define default consent states before any Google tag or event command can run.
Update consent states immediately after the visitor submits a choice.
Configure regional defaults according to your legal requirements and consent policy.
Use built-in consent checks for supported Google tags and explicitly configure consent requirements for third-party tags in Google Tag Manager.
Test both granted and denied scenarios in Tag Assistant and verify that tags, cookies, and outgoing requests behave as intended.
Implement separate consent handling for every advertising or analytics platform that requires it.

Choosing the right implementation

Basic Consent Mode is appropriate when the organization’s policy requires Google tags to remain completely blocked until the visitor opts in. Advanced Consent Mode is better suited to businesses that want stronger measurement and modeling while still changing tag behavior based on consent. The right approach depends on legal requirements, risk tolerance, measurement needs, and the capabilities of the selected CMP.

Need help implementing Google Consent Mode?
I design, audit, and troubleshoot Consent Mode implementations for Google Analytics 4, Google Ads, and Google Tag Manager. The work includes CMP integration, consent-state configuration, regional settings, tag-level consent checks, and end-to-end validation for both granted and denied scenarios.
Contact me to discuss your Google Consent Mode setup.