Implementing Google Consent Mode with Usercentrics, step by step guide

This guide is meant to provide you with a complete walk-through on how Google Consent mode can be implemented using Usercentrics CMP, and the minimum info to recognize a Google Consent mode implementation and troubleshoot it. This guide will not explain how to block scripts or GTM tags. About that, please refer to the following articles: 

• Configuring Google Tag Manager tags to be consent aware
• Manually blocking services prior consent

You can start here and read through, or go directly to the section you need: 

About Google Consent Mode in short

Setting up Google Consent mode with Usercentrics

• The consent default event
• The consent update event 

How to check if Google Consent Mode is properly implemented

About Google Consent Mode in short

Google Consent mode is an additional implementation required by Google that adjusts the tracking behavior of Google products (like Google Analytics or Google Ads) based on the user's consent choice. A complete implementation requires: 

• The "Consent Default" event, which loads first on every page,
• The "Consent Update" event, which loads on the page after the user makes a consent choice.

These events must happen on the same page load and need to set the consent values of the 4 parameters that are part of Google Consent mode V2, namely: 

• ad_storage
• analytics_storage
• ad_user_data
• ad_personalization

These parameters can receive two values, either granted or denied.

Depending on how scripts are fired relative to the consent choice, Google Consent mode can have two types of implementation: 

• Basic: no script is loaded on the page until a consent choice is made
• Advanced: scripts are loaded before a consent choice is made, and are adjusted depending on the values of the 4 parameters. 

For a more detailed explanation of Google Consent mode and its requirements, you can refer to Google's official documentation: 

• Set up consent mode

You can also learn more about the differences between basic and advanced implementations in our detailed article Advanced and Basic Google Consent Mode v2.

Setting up Google Consent mode with Usercentrics 

The consent default event

As described above, the implementation of Google Consent mode requires the loading of the Consent Default event on every page. The event has to set the default consent for the 4 parameters based on the legal framework required for that specific user. For example, a European user who falls under GDPR requires that all parameters are set as denied in the default event. Usercentrics CMP does not handle the default event natively, so it can either be added manually with a script or it can be handled via the Usercentrics GTM template. 

Adding the default event manually 

The consent default event can be added manually via the following script: 

<script>
gtag('consent','default',{
    'ad_storage':'denied',
    'ad_user_data':'denied',
    'ad_personalization':'denied',
    'analytics_storage':'denied',
    'functionality_storage': 'denied',
    'personalization_storage': 'denied',
    'security_storage': 'granted'
});
</script>

Depending on your implementation, you might also need to define the gtag function and the dataLayer object if these have not been defined previously. In this case, the script will look as follows: 

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

The script for the default event needs to be added as high as possible in the head of the page, after the banner, so that it is loaded before other tracking scripts. If it does not include any event for a Google product, like for example the configuration for GA4 as described in the next code block, it does not need to be adjusted. 

gtag('config', 'STREAM_ID')

If you need to set the default event and other scripts for Google products, you can keep them in separate elements and adjust only those that track the user's behavior on the page. 

Adding the default event via the Usercentris template

The GTM template for Usercentrics has a dedicated section to handle the default event, as well as multiple regions. In the template, scroll down to the section that reads "Default Consent State" and click on " Add region". 

In the following menu, add a region if necessary, using the ISO code for the specific region or regions separated by a comma. If no region is added, this setting will be used globally. After that, add the default value for the 4 parameters based on the legal requirement for that region, and click on "Add". 

Save the tag and publish the GTM container.

The consent update event

The banner is set to push the update event by default. Still, make sure that Google Consent mode is enabled for your configuration. You can find the toggle in the admin interface following the path: Configuration > CMP Settings