Google Consent Mode 2.0¶

Google Consent Mode v2 (GCM v2) became mandatory for all Google Ads advertisers targeting EU traffic from March 2024. Waulter supports both Basic and Advanced modes out of the box — the SDK handles all consent signalling automatically.

What is Google Consent Mode?¶

Google Consent Mode is an API that lets you communicate your visitors' consent state to Google tags (Analytics, Ads, Floodlight). Instead of blocking or loading tags based on consent, you signal the consent state and let Google adjust tag behaviour accordingly.

Key benefit: You maintain a single set of tags on the page. Google tags respond to consent signals without you having to add or remove tags.

The 7 consent types¶

GCM v2 defines seven consent signals:

Basic Mode vs Advanced Mode¶

How Advanced Mode works¶

In Advanced Mode, Google tags operate in a privacy-preserving state before the visitor consents:

1. Tags load but do not set cookies
2. Tags send cookieless pings — aggregated signals without user identifiers
3. Google uses these signals for conversion modelling (estimating conversions from unconsented visitors) and audience estimation
4. Once the visitor consents, tags switch to full measurement mode

Waulter's automatic GCM integration¶

When you deploy Waulter with useGtm: true, the SDK handles all GCM signalling automatically. You do not need to write any consent mode code yourself.

What happens automatically¶

sequenceDiagram
    participant Page as Page Load
    participant SDK as Waulter SDK
    participant GTM as Google Tag Manager
    participant Tags as Google Tags

    Page->>SDK: SDK loads
    SDK->>GTM: dataLayer.push({ event: 'gtm.init_consent' })
    SDK->>GTM: gtag('consent', 'default', { all: 'denied' })

    alt Advanced Mode
        Tags-->>GTM: Send cookieless pings (no cookies set)
    else Basic Mode
        Note over Tags: Tags wait — no activity
    end

    Page->>SDK: Visitor clicks "Accept All"
    SDK->>GTM: gtag('consent', 'update', { analytics_storage: 'granted', ... })
    SDK->>GTM: dataLayer.push({ event: 'Waulter:Decision' })
    GTM->>Tags: Consent granted — tags fire with full measurement

Step by step:

1. SDK starts — pushes gtm.init_consent and sets all signals to denied
2. Banner appears — visitor sees consent options
3. Visitor decides — SDK maps accepted purposes to GCM signals and pushes a consent update
4. Tags respond — Google tags that were waiting for consent now fire

Default consent state¶

On every page load, the SDK sets all signals to denied:

gtag('consent', 'default', {
  ad_personalization: 'denied',
  ad_storage: 'denied',
  ad_user_data: 'denied',
  analytics_storage: 'denied',
  functionality_storage: 'denied',
  personalization_storage: 'denied',
  security_storage: 'denied'
});

This ensures no Google tags collect data before the visitor has consented.

Consent update after decision¶

After the visitor decides, the SDK builds a consent update from the accepted purposes:

// Example: visitor accepted analytics + advertising purposes
gtag('consent', 'update', {
  ad_personalization: 'granted',
  ad_storage: 'granted',
  ad_user_data: 'granted',
  analytics_storage: 'granted',
  functionality_storage: 'denied',
  personalization_storage: 'denied',
  security_storage: 'granted'
});

See Purposes — Purpose-to-GCM signal mapping for which purposes map to which signals.

Configuring GCM mode¶

In the Waulter dashboard¶

1. Open your website configuration in the dashboard.
2. Navigate to the Google Consent Mode section.
3. Choose Basic or Advanced mode.
4. Save the configuration.

The mode is stored on the configuration (not in the SDK). This means you can switch modes without changing any code on your site.

In the GTM template¶

If you use the Community Template, select the GCM Mode in the template fields:

Testing GCM integration¶

Using GTM Preview + Tag Assistant¶

1. In GTM, click Preview and enter your site URL.
2. The Tag Assistant panel opens alongside your site.
3. Check the Consent tab in Tag Assistant:

Using browser Developer Tools¶

1. Open the Console tab.
2. Enable debug: true in your WaulterConfig.
3. Look for consent-related log entries showing default and update calls.
4. Check the Network tab for Google tag requests — in Basic Mode, no requests should appear before consent.

Common testing scenarios¶