In today’s data-driven world, privacy isn’t just a concern for users—it’s a requirement. With regulations like GDPR and CCPA raising the stakes, businesses have to manage user consent more carefully than ever. And while many marketing teams have their client-side tracking setups sorted, the growing shift to server-side tracking adds a whole new layer of complexity.
Server-side tracking gives you better control over what data you collect and how you process it. But with great power comes great responsibility. You need to ensure user consent isn’t just captured but respected across the board—whether you’re tracking on the client or server side. This post will dive into why server-side tracking matters, how you can manage consent, and the technical and ethical challenges you’ll face.
Table of Contents
Why Server-Side Tracking and Tagging is Important for Data Control and Privacy
How Marketing Teams Can Ensure Compliance with Privacy Laws in Server-Side Tracking
Common Challenges Marketing Teams Face in Implementing Consent for Server-Side Google Tag Manager
Ethical and Technical Implications of Managing Consent in a Hybrid Client-Server Environment
Best Practices for Managing Consent in Server-Side Tracking and Tagging
Why Server-Side Tracking and Tagging is Important for Data Control and Privacy
Complete Control Over Data
Let’s be honest—when you use client-side tracking, you trust third-party JavaScript libraries to do their job. But the reality is you don’t have full visibility into what data they’re collecting or where it’s being sent. That’s a pretty significant risk.
With server-side tracking, you regain control. You decide what data gets collected, how it’s processed, and where it’s sent. Need to hash sensitive data before sending it off? No problem. Want to ensure your setup aligns with privacy by design principles? Done. Server-side tracking allows you to customize and filter data before it leaves your server, which means less risk of exposure and more control over privacy.
Enhanced Privacy
Let’s talk privacy. Server-side tracking offers more flexibility for respecting user consent. Unlike client-side tracking, where third-party scripts can get messy, server-side setups give you better control over what’s actually being collected. No more wondering if an ad network is grabbing more data than you intended—everything is centralized on your server.
This also means easier compliance with privacy regulations like GDPR. When you control the data flow, it’s easier to minimize what you collect, anonymize sensitive information, and ensure you’re only gathering what you’ve explicitly received permission for.
Improved Data Security and Quality
With client-side tracking, you’re dealing with browser limitations, ad blockers, and other disruptions. That’s a lot of variables that can mess with your data. Server-side tracking, on the other hand, bypasses those headaches by processing data on your server, ensuring more consistent and accurate information.
It’s also a major security boost. Since server-side tracking is less vulnerable to interception or tampering, you’re reducing the risk of data breaches. Plus, you’re cutting out third-party scripts that can potentially compromise your users’ privacy. In short, server-side tracking not only secures your data but also helps keep it clean and reliable.
How Marketing Teams Can Ensure Compliance with Privacy Laws in Server-Side Tracking
When it comes to privacy laws, the big ones like GDPR and CCPA don’t mess around. So, how do you ensure you’re compliant when adding server-side tracking into the mix?
Handling Consent Across Client-Side and Server-Side
First things first—you need to make sure consent is respected in both your client-side and server-side setups. Most teams already handle client-side consent via a Consent Management Platform (CMP). The key is making sure that the user’s consent state is passed from the client-side GTM (Google Tag Manager) to the server-side GTM. This way, when you process events server-side, you can be confident that only data the user has consented to is collected and shared.
Choosing Between Server-Side Tagging and Server-Side Tracking
There’s a difference between server-side tagging and tracking, and that difference impacts how you handle consent. In server-side tagging, the event gets triggered by the client and sent to the server-side GTM, where you decide what to do with it. In server-side tracking, the backend (think your server) recognizes an event (like an order submission) and sends that data to your analytics platform. In either case, you need to ensure that the user’s consent state is available before sending any data.
Leveraging CMPs for Seamless Consent Management
Your CMP is your best friend here. When a user interacts with your consent banner, the CMP captures their preferences and makes them available in both client-side and server-side environments. This ensures you’re not accidentally collecting or sharing data without the user’s explicit consent. It’s crucial for compliance and user trust.
Common Challenges Marketing Teams Face in Implementing Consent for Server-Side Google Tag Manager
Server-side tracking sounds great, but it’s not without its challenges—especially when it comes to managing consent. Here are a few hurdles you might encounter and how to get over them:
Passing Consent from Client-Side to Server-Side
The main challenge here is ensuring that consent data is transferred from the client side to the server side. You can handle this by passing the user’s consent state as a variable from your client-side GTM to the server-side GTM. This way, your server-side GTM can evaluate consent before doing anything with the data.
Managing Compliance Across Platforms
It’s easy to ensure compliance on your client-side GTM, but server-side compliance adds another layer. You have to ensure the user’s consent is respected no matter where the event is processed. The best approach? Use a unified consent strategy—sync your consent preferences across all platforms to avoid compliance gaps.
Third-Party Tags and Consent
Not all third-party platforms support out-of-the-box consent checks. Facebook Conversion API, for example, requires a little more work. You must set up custom triggers in sGTM to ensure you’re not firing events unless the user consents.
Ethical and Technical Implications of Managing Consent in a Hybrid Client-Server Environment
Ethical Implications
With client-side tracking, users can see what’s happening under the hood. They can inspect what data is being collected and where it’s going. But with server-side tracking, that transparency disappears. This creates an ethical gray area—businesses might be tempted to bypass consent rules if users can’t see the data flow. The ethical path is simple: always respect user consent, no matter how invisible the tracking.
Technical Implications
Technically, managing consent across hybrid environments means syncing data between your client-side and server-side setups. This is where CMPs play a key role—they help ensure that consent flows seamlessly between both environments. Whether you’re using server-side tagging or server-side tracking, you need to make sure the user’s consent state is respected across the board, even if it’s not immediately visible.
Best Practices for Managing Consent in Server-Side Tracking and Tagging
Managing consent for server-side tracking requires more than just technical implementation. It involves a strategic approach that balances compliance, user experience, and operational efficiency. Below are some essential best practices for achieving this:
Use a Consent Management Platform (CMP) Integrated with GTM
The first step in managing consent across client and server environments is integrating a Consent Management Platform (CMP) with both your client-side GTM and server-side GTM. CMPs act as a gateway for user preferences, ensuring compliance with privacy regulations like GDPR and CCPA.
How it works:
The CMP captures user consent when they interact with your cookie banner. This consent data is stored and made available to both the client-side and server-side GTM, ensuring that only tags aligned with user consent are triggered. For example, if a user opts out of marketing tracking but agrees to analytics, the CMP can ensure that only the analytics tags are fired.
Why it’s important:
CMP integration is essential for respecting user choices, and it simplifies compliance with regulations that require informed and explicit consent before data collection. Additionally, CMPs ensure that the data passed to third parties like Google Analytics, Facebook, or advertising networks is only collected and processed with the user’s approval.
Further readings:
https://piwik.pro/blog/server-side-tracking-first-party-collector/
https://cookieinformation.com/resources/blog/what-is-server-side-consent/
Synchronize Consent Across Client and Server
One of the most important considerations in a hybrid setup is ensuring that consent collected on the client side is respected on the server side. User preferences flow consistently between both environments.
Best practice:
Ensure that the consent status collected by the CMP is passed through a data layer variable or a custom parameter from the client-side GTM to the server-side GTM. This allows the server-side to evaluate consent before triggering any third-party tags or events, like sending data to conversion APIs or analytics platforms. For example, if a user denies consent for marketing cookies, the server-side system should prevent that data from being shared with advertising platforms.
Why it’s important:
Without proper synchronization, there’s a risk of violating user consent by processing data in ways that haven’t been authorized. This synchronization ensures compliance with privacy laws and reinforces trust by guaranteeing that user preferences are respected across all platforms.
Further reading:
https://stape.io/blog/server-side-consent-management-with-sgtm-and-cookiebot
https://stape.io/blog/consent-settings-for-server-gtm-tags
Leverage Server-Side Tagging for Greater Flexibility
Moving more of your data processing and consent handling to the server-side GTM allows for greater control and flexibility over what data gets shared with third parties.
Best practice:
Use the server-side GTM to centralize data processing. For example, instead of triggering multiple events on the client side (which can lead to complications due to browser restrictions or ad blockers), send a single event to the server-side GTM. There, you can apply consent-based logic to decide whether to forward the data to analytics or marketing platforms. You can also enrich the data, anonymize it, or filter it to further respect privacy regulations.
Why it’s important:
Server-side processing reduces your exposure to client-side issues like browser tracking prevention mechanisms or ad blockers, which can interfere with data collection. Centralizing consent handling on the server side ensures a smoother, more reliable process, ultimately improving data quality while maintaining compliance.
Implement Consent Segmentation
Not all data requires the same level of consent, and different types of data may require separate levels of user permission. For example, users may consent to essential cookies but not to marketing or advertising cookies.
Best practice:
Segment your consent options to give users more control. Use granular consent preferences to differentiate between analytics, marketing, and functional cookies. Make sure each segment is independently respected in both client-side and server-side processing. For instance, a user might agree to functional and analytics cookies, allowing data to flow to your analytics platforms, but block marketing cookies, which prevents data from being shared with ad platforms.
Why it’s important:
Offering granular consent builds user trust and ensures compliance with privacy regulations that require clear and specific consent. It also prevents unnecessary data from being collected, reducing potential risks and improving user experience.
Regularly Audit and Review Consent Handling Processes
Consent management is not a one-time setup. Regular audits of your consent management processes are crucial to ensuring compliance as regulations evolve and new technologies emerge.
Best practice:
Conduct frequent audits of your server-side tracking setup to verify that consent data is consistently passed and respected across all platforms. Review how data is collected, processed, and transmitted, ensuring that it aligns with the latest privacy regulations. Test your CMP integration regularly to make sure that consent preferences are accurately captured and implemented.
Why it’s important:
Regular audits help identify gaps or inconsistencies in your consent management process, ensuring that your business remains compliant and transparent. They also reduce the risk of fines or penalties from privacy violations and give you the opportunity to optimize your tracking and consent strategies.
Be Transparent About Data Collection
Even though server-side tracking is less visible to users, transparency is key to building trust and maintaining compliance with data privacy laws. Make sure your users know what data is being collected, how it’s being processed, and how they can control it.
Best practice:
Clearly communicate your data collection practices through an updated privacy policy. Explain how both client-side and server-side tracking work, what data is being collected, and for what purposes. Allow users to easily change their consent preferences and provide a Consent Management Interface for users to review and update their choices.
Why it’s important:
Transparency is not just a legal requirement under GDPR and other privacy regulations, but also a way to foster long-term trust with your users. Providing clear and accessible information about how you handle their data ensures a positive user experience and increases user confidence in your privacy practices.
By following these best practices, marketing teams can effectively manage consent in server-side tracking, ensuring compliance with privacy laws while building trust with their users. Properly handling consent across both client-side and server-side environments not only protects your business from regulatory risks but also strengthens your relationship with your audience.