Google Consent Mode is a website measurement solution that respects a user's consent for cookies. It allows you to continue making data-driven marketing and business decisions while helping you comply with data privacy regulations.

But is Consent Mode worth using? How does it work? And where do you start?

How Does Google Consent Mode Work?

In short, Consent Mode adjusts the behaviour of Google tags - Google Analytics, Google Ads, and Floodlights - based on a user's consent choices.

Let's assume you have a cookie preferences pop-up that displays to every user when they first visit your website.

With Consent Mode implemented, Google tags will fire regardless of the consent given, but the exact behaviour of those tags will differ depending on what cookies the user has agreed to.

This removes the need for complex tag firing conditions or creative customisations to tag snippets. It's a much neater solution to ensure your Google tags are complying with regulations and respecting user consent.

How Does Consent Mode Actually Work?

Consent Mode works thanks to two new parameters, 'analytics_storage' and 'ad_storage', which can either be granted or denied.

When they're set to true (i.e. the website visitor has consented to cookies for both analytics and advertising) Google tags will fire as normal. This includes reading and setting cookies on the user's browser.

If a user does not provide consent for advertising cookies by setting 'ad_storage' to denied, the Google Ads and Floodlight tags will fire as 'anonymous pings'.

Limited information is passed to the ad platforms with these pings, in the form of function information and aggregate data. No advertising cookies are read or set, removing the ability to identify a user or link a specific web action back to ad interactions.

Google Analytics tag behaviour is dependent on both tag settings:

  • If analytics_storage is set to denied, all GA hits are sent as 'cookieless pings'. This is because GA can't use cookies in this state. It's impossible to connect multiple hits together as a coherent session, identify a returning visitor, or add a user to a remarketing list.
  • If a user consents to analytics cookies, but not to advertising cookies, the GA tags will fire as normal, but data collection is limited to behaviour and conversion. This means the user is opting out of advertising features like remarketing lists and no data is used to power Google Signals.
  • If a user consents to both analytics and advertising cookies, the Google Analytics tags will fire as normal, reading and setting cookies.

What are the Benefits of Google Consent Mode?

Assuming your website is currently GDPR compliant - and your analytics and advertising tags respect a user's consent to cookies - it's likely that you’re only firing Google tags for a subset of the visits your website receives.

Additionally, within the visits that you're able to track, you may only be collecting data once consent has been given, so you are missing out on a portion of activity.

Consent Mode allows you to increase the window of data collection, and give you greater coverage of website measurement. While the anonymous data Google Analytics, Google Ads, and Floodlight tags are collecting is never surfaced in your reports, it is being put to good use.

Since April 2021, conversion modelling for consent mode has been available in Google Ads. Following a 'training period' for the model, modelled conversions will begin appearing in your Conversions and Conversions Value columns.

This modeling helps fill in the blanks when users choose to opt-out of cookies, where it's impossible to connect ad interactions with conversions. The machine learning Google applies is based on the data that can be observed, historical trends, and the anonymous data now being collected.

Modelled conversions, along with tracked conversions, help power bidding strategies so you can continue making the most of Google's automated solutions.

At present, modelling like this isn't available in Google Analytics - however, we're confident it's coming soon. Modelled conversions for cross-channel journeys are already included in GA4, so it may only be a matter of time before this is expanded to cover consent mode as well.

How Do I Start Using Google Consent Mode?

Firstly, Consent Mode is not a consent management platform. In order to use Consent Mode, you already need to have a solution in place to collect user consent on your website.

Full details on how to implement consent mode can be found in Google's technical documentation, but we'll summarise the key points here.

1. Configure Default Behaviour

    Add a code snippet to every page of your website to initially deny cookie consent. This will stop tags firing and using cookies before a user's consent status is known.

    This can also be achieved through Google Tag Manager, but the tag needs to be fired using the new Consent Initialization trigger to ensure it's loaded before any other triggers in the container.

    2. Update Behaviour

      Once a user gives or denies consent, this information needs to be made available for the Google tags.

      This can be done through hardcoded gtag API calls, tags in GTM, or through an integration with your consent management platform. This last option is certainly the easiest so check if your provider has already developed an integration.

      3. Test and Launch

        Test that your tags are behaving as you would expect with Consent Mode enabled, with a combination of GTM debug, GA real-time, and checking your browser for cookies.

        Once you're happy it's working as expected, push it live and remove any previous consent tagging solutions you had for Google tags.

        Final Thoughts

        Google Consent Mode is relevant to any advertiser using Google tags for measurement, who needs to adhere to privacy regulations such as GDPR. And with the need for privacy-first measurements only growing in the coming years, now is the time to make use of this Google solution.