What is server-to-server tracking and how does it work?
You’ve probably felt it: the data you rely on for campaign optimization is becoming less reliable. Client-side tracking, which has powered digital marketing for over a decade, faces increasing limitations from browser restrictions, privacy regulations, and ad-blocking software.
At the same time, businesses need more accurate attribution data to optimize their marketing spend effectively. Server-to-server tracking provides a solution by moving data collection from the user’s browser to your own infrastructure.
This approach gives you direct control over how customer data flows to advertising platforms and analytics tools. You don’t have to hope that browser-based scripts work correctly, because you manage the entire data pipeline yourself.
What is server-to-server (S2S) tracking?
Server-to-server tracking (S2S), also known as server-side tracking, is a method of data collection in which your server communicates directly with third-party platforms like Google Analytics, Facebook, or advertising networks. Instead of relying on JavaScript code running in the user’s browser, your backend system handles the data transmission.
Rather than asking the user’s browser to tell Facebook about a purchase, your server tells Facebook directly. The user’s device doesn’t need to load multiple tracking scripts or make dozens of requests to different advertising platforms.
What is server-to-server tracking in Google Tag Manager?
Google Tag Manager introduced server-side tagging to address the limitations of traditional client-side implementations. This core feature essentially enables you to run a version of Google Tag Manager on your own server infrastructure, rather than just in the user’s browser. It’s worth noting that this capability is not enabled by default.
It works by sending your website data to a server-side Google Tag Manager container that you control. This container processes the data according to your rules and then forwards relevant information to your chosen platforms, like Google Analytics, Google Ads, or third-party tools.
The server-side container runs either on Google Cloud Platform or your own infrastructure. It receives HTTP requests from your website, processes them through your configured tags and triggers, and sends the resulting data to destination platforms via their application programming interfaces (APIs).
Read more about server-side tagging using Google Tag Manager.
S2S tracking vs. client-side tracking
The main difference between server-side and client-side tracking is where data processing happens and who controls the flow of information.
Let’s compare the two further.
Read more about the difference between client-side vs. server-side architecture.
What are the uses of server-to-server (S2S) tracking?
Server-to-server tracking is becoming essential for modern marketers, developers, and data teams. By sending data directly from your backend systems, S2S tracking makes your customer insights more accurate, more reliable, and more powerful.
Here’s how it works across different use cases.
Ad platforms integration
Platforms like Facebook (through the Conversions API) and Google Ads (via Enhanced Conversions) use server-to-server data to improve conversion tracking. Instead of relying on browser-based pixels that can fail or get blocked, your server sends the data directly to the platform.
Server-to-server conversion tracking means more accurate attribution, more reliable reporting, and ultimately, better ad performance.
Affiliate marketing measurement
Affiliate programs also benefit from server-to-server tracking because it eliminates disputes over conversion attribution. By having your server directly transmit conversion events to affiliate networks, you remove ambiguity about whether a conversion was properly tracked.
Traditional affiliate tracking, which relies on browser redirects and tracking cookies, can be unreliable. With server-to-server tracking, your system tells the affiliate network exactly when and where a conversion happens.
Mobile app attribution
App store restrictions and device limitations have always made mobile attribution challenging. Server-to-server tracking enables mobile marketing platforms to receive conversion data directly from your app’s backend.
This approach works particularly well for in-app purchases and subscription conversions. S2S tracking can help to ensure accurate attribution, regardless of the user’s device settings or network conditions.
Advanced analytics pipelines
Server-to-server tracking is particularly useful if you’re managing complex data flows across teams and platforms. It enables you to build sophisticated data pipelines that transform and route customer data to different destinations based on your specific requirements.
You can route raw events to your data warehouse, send refined conversion data to your ad tools, and push curated metrics to business intelligence dashboards from one trusted source.
Benefits of server-to-server tracking
Moving tracking to the server side is both a technical and a strategic upgrade. Whether you’re scaling performance marketing or simplifying data compliance, server-to-server tracking provides valuable benefits:
- Improved data accuracy: Your conversion data becomes more complete when it doesn’t depend on browser behavior. When users close tabs quickly, have slow internet connections, or use ad blockers, they won’t create gaps in your attribution data.
- Increased data control: You decide exactly what information gets sent to each platform. Want to send conversion data to Google Ads but exclude personally identifiable information? Your server-side setup can transform data before transmission.
Cost optimization: Better attribution data leads to smarter budget allocation across marketing channels. When you can accurately track which campaigns drive conversions, you stop wasting money on underperforming audiences.
Discover the full list of benefits of using server-side tracking.
Server-to-server tracking and global privacy regulations
Server-to-server tracking gives you granular control over consent implementation. That matters, as privacy regulations like the General Data Protection Regulation (GDPR) in the EU and the California Privacy Rights Act (CPRA) require explicit consent for data processing.
When a user opts out of marketing cookies, your server must immediately stop sending their data to advertising platforms. You don’t need to wait for browser-side consent management platforms to update dozens of tracking scripts.
When you control the transmission process, it also makes data minimization easier. Instead of sending all available data points, you can filter information based on your privacy policy requirements and user consent levels.
Cross-border data transfers also become more manageable. Your server can keep European user data within EU boundaries while still enabling marketing measurement and optimization.
How does server-to-server tracking work?
Let’s look at how the S2S process works.
1. A user interacts with your website or application
When someone interacts with your website or app, such as by making a purchase or submitting a form, your frontend doesn’t rely on third-party scripts in their browser. Instead, it sends that event data directly to your server.
2. Your server receives this event data
Once your server receives the event, it processes the data based on your business logic. This processing step is where the power of server-to-server tracking becomes clear. You can:
- Validate incoming data
- Apply privacy preferences
- Check user consent preferences
- Format and transform the data for specific destinations
This step gives you full control over how the data is handled moving forward.
3. Your server communicates with third parties
After processing, your server sends the refined data to third-party platforms like Google Analytics, Facebook (via Conversions API), or your own data warehouse, all via direct API calls. Each platform only receives what you decide to send, and in the right format.
The entire process typically takes just milliseconds and doesn’t depend on the user’s browser capabilities, internet connection speed, or privacy settings.
How to set up server-to-server tracking?
There’s no one-size-fits-all S2S setup. Some teams build everything from scratch, others rely on ready-made platforms. Most businesses choose a mix of both, combining custom development with proven infrastructure to get the best of both worlds.
1. Start with a plan
Begin by auditing your current tracking setup. What events are you capturing? Where does that data go? Map your customer journey and highlight the conversion points that matter most. These are the events that you need to track accurately and consistently.
Then, choose how you’ll build your solution. A fully custom setup gives you full control, but it takes time and resources. Tools like Google Tag Manager’s server-side container or the Usercentrics server-side tracking solution can speed up the process without sacrificing flexibility.
2. Set up your technical foundation
Create server endpoints that can receive event data from your website or app. These endpoints should handle:
- Authentication
- Data validation
- Logging for any errors or failed requests
Next, connect your server to the platforms where the data needs to go. That means setting up API credentials, learning what each platform expects, and making sure you have solid error handling in place.
3. Use server-side tagging platforms to simplify setup
Server-side tagging platforms, like Usercentrics’ solution, handle much of the technical complexity for you. Your developers will not need to write a single line of code. Instead, you’ll have a visual interface where you can define data flows, set consent rules, and map events to their destinations. Making it easy to use while saving you time and resources.
Our tool comes with pre-built templates for GA4, Google Ads, Meta (CAPI), and more. So you can quickly get started. But if you have any questions along the way, our detailed documentation will guide you through the installation process.
4. Test, monitor, and validate
No matter how you implement your tracking setup, you’ll need to test it. Compare your new server-side tracking with your existing browser-based system to spot any gaps. Monitor response times, error rates, and delivery success to verify that your data is flowing as expected.
Drawbacks of using S2S tracking
Server-to-server tracking offers major advantages, but it’s not plug-and-play. There are some trade-offs you should be aware of before making the switch.
- Implementation complexity: Unlike dropping a client-side script into your site, S2S tracking requires real infrastructure. You’ll need server environments, API connections, and the ability to monitor and maintain tracking.
- Development resources: Building and maintaining a server-side setup takes time. Your developers will need to handle the initial integration as well as future updates.
- Attribution challenges: Some ad platforms still rely on browser-based signals to model attribution. With S2S, you might lose some of that detail, especially around view-through conversions or multi-touch journeys.
- Cookie limitations: S2S helps bypass many browser limitations, but it’s not a total replacement. For user identification, personalization, or cross-site tracking, client-side components may still be necessary.
- Cost considerations: With custom infrastructure comes added cost. It’s an investment, especially compared to simpler client-side tools.
Is server-to-server tracking right for me?
Server-to-server conversion tracking offers powerful benefits, but it’s not the right fit for every business. Whether or not to invest depends on your current challenges, technical resources, and the role data plays in your marketing strategy.
When S2S tracking makes sense
If your website performance is suffering from heavy client-side tracking or if you’re seeing major attribution gaps due to ad blockers, S2S tracking can provide a more reliable alternative.
It’s also a strong choice if you need detailed control over what data is shared for privacy compliance purposes, or if marketing performance is a key growth lever and attribution accuracy impacts your bottom line.
You also need to have the technical resources to manage implementation and maintenance.
When it might not be the right time for S2S tracking
On the other hand, if your current tracking setup is delivering reliable data, you may not need to make the switch. Businesses with limited development capacity or smaller marketing budgets may find the investment harder to justify.
Similarly, if browser restrictions aren’t significantly impacting your data quality, a client-side solution might still be sufficient.
The decision comes down to cost vs. value. For teams that rely on precise, consistent data to drive revenue, S2S tracking can offer a competitive edge. For others, it may be a future consideration rather than an immediate priority.
Moving beyond browser limitations
Server-to-server tracking represents a shift toward more sustainable marketing measurement. As privacy regulations evolve and browsers increasingly restrict tracking capabilities, businesses need measurement approaches that don’t solely depend on client-side scripts.
The transition may require upfront investment or technical setup. However, the long-term benefits of reliable data collection, improved page performance, and better privacy compliance often justify the investment.