Is Google Advanced Consent Mode Privacy-Compliant?

Businesses lose valuable data every day—whether due to strict privacy regulations or technologies like ad blockers and browser tracking restrictions that prevent user data from being collected. We've seen alarming numbers among our clients: data losses of up to 70% are not uncommon.

You might be facing the same issue: your website or online store provides incomplete data in Google Analytics (GA4) and Google Ads. Conversions are missing, events are misattributed, and the number of newsletter subscribers in your CRM doesn’t match your tracking data.

This often raises a critical question: How accurate is my tracking data—and how can I minimize data loss?

In this blog post, we’ll dive deep into these questions. We’ll explore the most common causes of data loss in web tracking and show you how to restore data accuracy. Our main focus will be on Google Consent Mode, particularly the enhanced version—Google Advanced Consent Mode—available since March 2024.

Finally, we’ll address the key question: Is Google Advanced Consent Mode privacy-compliant? We’ll analyze it from the perspective of a tech-driven and privacy-conscious company.

Already familiar with Google Consent Mode? Click here to jump straight to the answer.

Stay tuned to learn how to collect tracking data reliably—while staying fully compliant with data protection regulations!

What Causes Data Loss? 

Comprehensive tracking is essential for accurate analysis and successful marketing campaigns. However, many businesses struggle with significant data losses that severely impact the effectiveness of analytics and optimization tools like Google Analytics. The causes of data loss can be categorized into three main areas:

Dependence on Consent Rate

Privacy regulations such as the GDPR require active and informed user consent before data can be processed. This consent is typically obtained through Consent Management Platforms (CMPs), also known as cookie banners. But what happens when users refuse to give their consent?

Direct impact of consent rates:

• A low consent rate directly leads to data loss. For example, if your consent rate is 60%, it means that 40% of potential data cannot be collected.
• Missing data weakens analysis: Events such as page views, conversions, and session duration from users who have not given consent are lost, significantly distorting data-driven decision-making.
• Limitations for tools like Google Analytics and Ads: Only data from users who have actively consented to tracking is available for analysis and marketing purposes.

Ad Blockers – The Silent Enemy of Tracking

Ad blockers have become widely used and specifically block JavaScript tags required for tracking data transmission.

Limitations despite user consent:

• Even if a user agrees to tracking via the cookie banner, ad blockers often prevent tracking data from being sent.
• Impact on campaign and traffic data: Paid advertising campaigns are particularly affected since crucial conversion and performance data may be lost.
• Increased data loss: Ad blockers further reduce the already limited data set, making precise analysis and optimized campaigns even more challenging.

Browser Tracking Prevention – The Decline of Cookies

Modern browsers like Safari, Firefox, and Chrome have implemented restrictions that either limit tracking capabilities or reduce the lifespan of cookies:

• Safari (Intelligent Tracking Prevention), Firefox (Enhanced Tracking Protection), and Chrome (stricter cookie limits) have built-in mechanisms to block tracking by default.
• Restrictions despite consent: These technologies can prevent tracking data collection even if users have explicitly given their consent.
• Additional data loss: Beyond losses from consent rates and ad blockers, browser restrictions further shrink the available dataset.

For example, if your cookie banner achieves a 60% consent rate, you’re already losing 40% of potential tracking data. On top of that:

• Ad blockers can block another 10-15% of the remaining data.
• Browser tracking restrictions can cut out an additional 5-10%.

In the worst-case scenario, you may end up with less than 40% of your potential tracking data—a significant loss that severely impacts your marketing and analytics efforts.

What Is Google Consent Mode and Why Is It Important?

Google, like all companies, must comply with data protection regulations. That’s why Google developed the Google Consent Mode. While this framework has been around for several years, one specific law has significantly increased its importance for both Google and businesses: the Digital Markets Act (DMA). This regulation primarily targets large tech companies, known as "gatekeepers," such as Google.

The Digital Markets Act (DMA) and Its Impact

The DMA came into effect on November 1, 2022, with the goal of promoting fair competition and strengthening consumer privacy online. One of its key provisions focuses on protecting consumer rights. As a result, companies like Google must now ensure that user data is collected only with proper consent.

This means Google can be held accountable for privacy violations. In practical terms, if Google services such as Google Analytics or Google Ads process user data without proper consent, the company faces potential sanctions.

Introduction of Google Consent Mode Version 2

Google had until March 6, 2024, to comply with the DMA requirements. One of the most significant updates was the enhancement of Google Consent Mode. With the introduction of Google Consent Mode Version 2, compliance became mandatory for businesses using Google services in the European market. This means that companies can only continue using Google Analytics and Google Ads in a legally compliant manner if they have properly implemented Google Consent Mode.

Why Google Consent Mode Is Essential

Google Consent Mode plays a crucial role in ensuring compliance with data protection laws while maintaining the effectiveness of tracking and advertising services. But what exactly is Google Consent Mode, and what versions are available?

In the next section, we’ll explore how it works and the key differences between its versions.

Google Consent Mode: A Must for Using Google Services Like Analytics

If you run a website, you are required to obtain active and informed user consent before processing data. This has been mandatory since the introduction of the General Data Protection Regulation (GDPR). However, what’s new is that you must now use Google Consent Mode if you want to continue using services like Google Analytics.

With Google Consent Mode, Google shifts the responsibility onto you: you must prove that you have obtained active user consent before processing any data—this is done via your cookie banner.

What Does Google Consent Mode Actually Do?

Simply put, Google Consent Mode transmits the cookie and privacy preferences from your cookie banner to the Google services you use. This happens through user signals triggered when a visitor clicks “Reject” or “Accept” in your cookie banner.

The latest version of Consent Mode (Version 2) introduces two new consent signals that inform Google whether the collected data can be used for marketing purposes or personalized advertising, such as remarketing.

If you do not implement Google Consent Mode, many Google services will be significantly restricted, making them almost unusable.

Two Versions of Google Consent Mode

Google Consent Mode offers two different versions, each with different impacts on your data collection:

• Basic Consent Mode – a simple implementation for websites that prioritize ease of setup over full data accuracy.
• Advanced Consent Mode – a more sophisticated approach that optimizes data collection while remaining privacy-compliant.

Let’s take a closer look at these two modes.

Basic Consent Mode: The Standard Option

The Basic Consent Mode is designed for website owners who prefer a straightforward setup process and are less concerned about having a fully comprehensive and precise data foundation for tools like Google Analytics. This mode is easier to implement because it requires fewer adjustments to Google Tags.

Fig.: How the Google Basic Consent Mode works

The principle is simple: In Basic Consent Mode, Google Tags are blocked by default until the user gives consent via the cookie banner. If a user clicks the "Accept" button, the Google Tags inform Google that data collection is allowed. However, if the user declines consent, the Google Tags send a corresponding signal to Google, preventing any data from being collected.

To compensate for the resulting data loss, Google uses a technique called conversion modeling. This method estimates the behavior of users who did not give consent by analyzing the behavior of those who did. While these modeled data points are not as precise as actual user data, they still provide valuable insights and are better than having no data at all.

Summary

The Basic Consent Mode primarily focuses on managing consent for analytics cookies and tracking technologies, while advertising cookies play a secondary role. It is particularly easy to implement and requires minimal technical expertise.

Advanced Consent Mode: The Advanced Mode 

The Advanced Consent Mode is designed for website owners who want to maintain the most accurate and complete data foundation possible. While integrating this mode is significantly more complex, it also offers greater customization options for Google Tags.

Fig.: How the Google Advanced Consent Mode works

One key aspect upfront: Unlike the Basic Consent Mode, the Advanced Consent Mode is optional. When a user gives consent, data processing works just like in the Basic Consent Mode. However, things get interesting when the user declines consent—because that’s when a crucial feature comes into play: cookieless pings.

These cookieless pings do not contain personally identifiable information, such as names or email addresses—at least in theory. Later, we’ll take a closer look at whether the Advanced Consent Mode truly complies with privacy regulations.

If a user rejects your cookie banner, the Advanced Consent Mode still sends cookieless pings to Google. The idea behind this is that businesses can still gather some level of data from users who declined cookies and use this information for Google Analytics and Google Ads.

This advantage can significantly impact the data available in Google Analytics and Ads. Depending on your cookie banner's consent rate, you can achieve up to 100% data coverage—even though some of this data is anonymized. But let’s be honest: In practice, what really matters is understanding how users interact with your website, rather than collecting personal data from individual users.

Summary

With Advanced Consent Mode, cookieless pings allow data collection from users who do not give consent, sending anonymized insights to Google without using cookies. However, there is valid criticism regarding whether this approach truly complies with data protection laws. That’s why we’ll now take a deeper dive into this issue.

Is the Advanced Consent Mode Privacy-Compliant?

One key question remains: Is Google’s Advanced Consent Mode truly compliant with data privacy regulations?

The main issue is that Advanced Consent Mode is a Google product. And when Google talks about cookieless pings, it remains unclear what data is actually being transmitted.

When tracking user data, most implementations rely on client-side tracking (more on that later). The problem? There is no independent control mechanism between your website and Google to monitor what user data is actually being shared.

A potential risk is that, despite the cookieless pings, IP addresses might still be sent to Google—raising concerns about how Google processes this information.

How Can This Risk Be Avoided?

To mitigate this issue, server-side tracking is recommended instead of client-side tracking. By implementing a dedicated server between your website and Google, you gain full control over what data is forwarded.

With server-side tracking, you can manage cookieless pings yourself and ensure that no personally identifiable information (PII) is unintentionally transmitted.

To better understand the differences between client-side and server-side tracking, let’s take a closer look at how both methods work in the next section.

Tracking Methods: Client-Side Tracking vs. Server-Side Tracking

When it comes to web tracking, there are two fundamental approaches: Client-Side Tracking and Server-Side Tracking.

Client-side tracking is the traditional and most widely used method because it is easier to implement and maintain compared to server-side tracking.

How Client-Side Tracking Works

With client-side tracking, data collection happens directly in the user’s browser. This means that tracking scripts run on the visitor's browser and send collected data directly to the tracking tool.

Fig.: How client side tracking works  

Client-Side Tracking Process:

1️⃣ A user visits a website or an online store.
2️⃣ The user’s browser loads and executes a tracking script that captures interactions such as page views, clicks, or scroll depth.
3️⃣ The collected data is then sent directly to a tracking tool like Google Analytics.

Advantages of Client-Side Tracking:

✅ Easy implementation: The code can be quickly integrated into existing websites.
✅ Extensive functionality: Many tools and plugins are optimized for client-side tracking.
✅ Real-time data processing: Collected data is immediately sent to analytics tools.

Disadvantages of Client-Side Tracking:

❌ Limited data accuracy: Ad blockers or cookie blockers can interfere with tracking.
❌ Privacy concerns: IP addresses and other personal data are transmitted directly, which can be legally problematic in certain regions.
❌ Performance issues: Too many tracking scripts can slow down website loading times, negatively impacting SEO rankings.

How Server-Side Tracking Works

Server-side tracking, also known as server-based tracking, shifts data collection from users' devices to a dedicated or external server.

This means that collected data is first processed on the website or app’s server before being forwarded to tracking tools like Google Analytics. As a result, website owners gain greater control over data processing and can selectively manage what information is shared with third parties.

Server-Side Tracking Process:

1️⃣ A user visits a website in their browser.
2️⃣ Unlike client-side tracking, tracking data is not stored in the browser or sent directly to Google. Instead, it is first transmitted to a dedicated server.
3️⃣ On this server, the data can be validated, cleaned, or anonymized before being forwarded to third-party tools like Google Analytics or Facebook Ads.

Fig.: How server side tracking works    

So, Is Google’s Advanced Consent Mode Privacy-Compliant?

This question doesn’t have a simple yes or no answer. The privacy compliance of Google’s Advanced Consent Mode depends largely on the specific settings and tracking setup used.

However, potential privacy risks can be significantly reduced by implementing certain measures.

Our Clear Recommendation:

If you plan to use Google’s Advanced Consent Mode, opt for server-side tracking instead of client-side tracking.

Why?

✅ Greater control over data – You decide which information is shared with Google.
✅ Improved privacy compliance – Personal data can be anonymized or filtered before leaving your server.
✅ Minimized privacy risks – By shifting data collection to your own server, you prevent uncontrolled data transmissions.

While Advanced Consent Mode can help provide a more comprehensive data set, it should only be used in combination with server-side tracking to mitigate legal risks.

What Do You Need for a Privacy-Compliant Tracking Setup with Google Advanced Consent Mode?

To use Google Advanced Consent Mode in a privacy-compliant way, you should consider the following elements in your tracking setup:

1. Google-Certified Consent Management Platform (CMP)

If you process personal data, a Consent Management Platform (CMP)—often referred to as a cookie banner—is a fundamental component of your privacy setup.

For Google Advanced Consent Mode to function correctly, it is crucial that your CMP is certified by Google. This ensures that user consent is properly collected and transmitted to Google.

💡 Tip: Google maintains a list of certified CMPs, which you can find here: Google’s Certified CMPs.

2. Google Advanced Consent Mode

Google Advanced Consent Mode allows for flexible data processing based on user consent preferences. However, the key question is: Do you have the technical expertise and resources to implement Consent Mode in a privacy-compliant manner within your tech stack?

A faulty implementation can jeopardize compliance and expose your business to legal risks, including warnings or fines. If your team lacks the necessary technical expertise, working with specialized service providers is highly recommended.

3. Server-Side Tracking

Compared to traditional client-side tracking, server-side tracking offers several advantages, particularly in terms of privacy and data control. For this reason, we generally recommend using server-side tracking when implementing Google Advanced Consent Mode.

⚠️ Important: Proper configuration is essential, even with server-side tracking. Only a correctly set up system ensures compliance with data protection laws while enabling optimized tracking.

Conclusion

Google Advanced Consent Mode can help businesses mitigate data loss caused by low consent rates, ad blockers, and browser tracking restrictions—partly by working with anonymized data. However, it is not a loophole to track users without valid consent. A Consent Management Platform (CMP) remains essential, even when using Advanced Consent Mode.

Whether Google Advanced Consent Mode is privacy-compliant depends on individual cases. However, under certain settings—especially when combined with server-side tracking—it can be used in a compliant way.

🔍 Our Recommendation: If your organization lacks in-house expertise on data privacy laws and tracking concepts, seek support from privacy and tracking specialists. Proper configuration is key to ensuring compliance with Google Advanced Consent Mode. Since every company has a unique tech stack and tracking setup, each implementation requires a tailored approach.

Getting the right guidance and configuration is essential to meet privacy requirements while benefiting from Advanced Consent Mode. If you're interested, we offer a free initial consultation—simply fill out the form below.