What is Google Consent Mode v2 and Why It’s Key for Your Google Ads Campaigns

For the past few months, Google has made the implementation of Google Consent Mode v2 (GCM V2) mandatory in order to continue collecting relevant data in Google Ads campaigns in Europe.
If you work with ads, analytics, or simply care about what happens on your website, this matters to you — a lot.

Below, we explain what it is, how it works, and why it can directly improve your advertising performance.

What is Google Consent Mode v2?

It’s a technology developed by Google that allows its tags (such as Google Ads or Google Analytics) to adapt based on user consent.
The idea is simple: if someone doesn’t give consent to be tracked, the tools behave differently, thus complying with privacy regulations such as the GDPR or the DMA.

In this V2 version, launched in 2024 and now mandatory, two new key parameters have been added to meet the requirements of the Digital Markets Act in Europe.

How does it work (without technical jargon)?

Google Consent Mode works with four parameters:

• ad_storage: whether advertising cookies can be used
• analytics_storage: whether analytics cookies can be used
• ad_user_data: whether user data can be sent to Google
• ad_personalization: whether ads can be personalised

Depending on what each user accepts or rejects in the cookie banner, these tags behave accordingly.
It’s not just about loading or not loading a cookie — it’s about how the information is managed.

What modes are available?

There are two ways to implement Google Consent Mode v2:

Basic mode

Tags are only activated when the user gives consent.
If they don’t, no data is collected.

Advanced mode (recommended)

Even if the user doesn’t accept cookies, anonymous pings are sent that don’t identify the person, but allow Google to estimate conversions using machine learning models.
This results in more useful data without compromising privacy.

Why is it important for Google Ads?

Because without Consent Mode V2 properly implemented, Google Ads stops receiving critical conversion data. Your campaigns will still run, but the results will be limited: clicks are tracked, but conversions are not.

According to Google, without this mode active you could lose up to 80% of conversions in your reports.
And that directly impacts automated optimisation, CPA, ROAS, budgets… everything.

Real benefits of the advanced mode

Implementing GCM V2 in advanced mode has very clear advantages:

• Conversion modelling: Google can estimate conversions from users who didn’t give consent, based on traffic patterns
• More accurate campaign reporting
• Compliance with European regulations without leaving your ad strategy in the dark

Does it make a difference?

Yes. Independent studies and internal data from companies that have correctly implemented GCM V2 show clear improvements:

• The cookie acceptance rate can increase by 7.8% to 15% with well-designed banners adapted to GCM V2
• The higher the consent rate, the more visible conversions, more analytics data, and better decisions
• Plus, anonymous pings help complete the picture without violating privacy

In short: better consent, better measurement, better campaigns.

Best practices to implement it

• Use cookie banners compatible with GCM V2 that inform clearly and provide easy options
• Implement Consent Mode using Google Tag Manager or directly with gtag.js
• Enable advanced mode if you run Google Ads campaigns in Europe
• Check that it’s working with tools like Tag Assistant or the diagnostics in your Google Ads account (“Consent Mode is active”)

What happens if you don’t implement it?

Your campaigns will stay active, but with incomplete data.
Your CPA might increase because many conversions won’t be recorded.
Performance will be harder to analyse, and the decisions you make could be based on an incomplete view of what’s actually happening on your website.

No data, no decisions

Google Consent Mode V2 is not just a technical or legal requirement.
It’s a key tool to avoid losing valuable data and continue making effective decisions in your campaigns.
And the best part? When well implemented, it can even improve performance.

Increasing the acceptance rate of cookies and having access to anonymised and aggregated information makes a big difference in your analytics and marketing results.

So if you haven’t set it up yet… now’s the time.