Google Consent Mode V2

Dastra natively supports Google Consent Mode V2. This page describes the prerequisites and the steps to enable it on the services of your cookie widget.

Dastra natively supports Google Consent Mode V2. This integration sends a consent_update signal to Google Tag Manager (GTM) as soon as a user expresses their consent, allowing Google tags to respect that choice before triggering any tracking.

Prerequisites

• The default consent snippet (see step 2) must be inserted in the <head> of your website, before Google Tag Manager is loaded.

• In Google Tag Manager, configure a "Google Tag" fired on all pages.

• The integration works with Google Ads (without personalization) and Google Analytics.

• If you use Google Ads conversion tracking or remarketing tags, make sure those tags are triggered only after consent, using a custom event such as dastra:consent:{service-slug} (example: dastra:consent:googleleads).

Step 1 — Enable Consent Mode V2 on the service

From the cookie widget integration, edit the relevant service (e.g. Google Analytics, Google Ads) and enable the "Consent mode V2" toggle. Once enabled, the Dastra banner will automatically send the consent_update signal to GTM each time a user interacts with the consent banner.

Then select the types of consent to be toggled for this service (all checked by default):

• ad_storage

• analytics_storage

• ad_user_data

• ad_personalization

Enabling Consent Mode V2 on a cookie widget service

The default consent snippet to insert in your website is displayed directly in the interface: use the Copy button to grab it, then follow step 2.

Step 2 — Place the default consent code before GTM

For Google tags to wait for the consent signal before firing, insert the following snippet before the GTM initialisation code in your page:

<script>
  window.dataLayer = window.dataLayer || [];
  function gtag() { dataLayer.push(arguments) }
  gtag('consent', 'default', {
    ad_storage: 'denied',
    analytics_storage: 'denied',
    ad_user_data: 'denied',
    ad_personalization: 'denied',
    wait_for_update: 500
  });
</script>

This snippet instructs Google tags to wait up to 500 ms for a consent_update signal before executing tracking. When the user accepts the relevant services, the Dastra banner automatically fires this signal and the tags can then execute.

This snippet must be placed before the GTM initialisation code. If it is loaded after GTM, Google tags may fire without waiting for consent.

Installation: hard-coded or via GTM?

The Dastra CMP script can be integrated directly into the page source (hard-coded) or loaded via GTM. Both methods are valid. However, hard-coded installation is recommended because it guarantees that the default consent snippet (above) executes before GTM — which is a prerequisite for Consent Mode V2 to work correctly.

Adding new services and resetting consent

Dastra does not automatically re-display the consent banner to visitors who have already made a choice when new services are added to the configuration. If you add a new tool (e.g. a new analytics service) and need to collect consent from existing visitors for that service, you must reset consent from the Dastra interface. A dedicated button in the widget configuration forces the banner to be shown again to all visitors on their next visit, including those who had already made a choice.

Going further

To trigger tags based on user consent (dataLayer events, blocking triggers...), see the dedicated Google Tag Manager page:

Google Tag Manager