Server side tracking & server side tagging, why it is gaining in importance

One of the most essential things in online marketing is the reliable tracking of user behavior. Unfortunately, however, this process is repeatedly hampered by a wide variety of challenges. Server side tracking is a solution to some of these challenges. In this article, I would therefore like to explain the advantages and disadvantages of server-side tracking and the differences to client-side tracking (the most widely used method). At the end, you'll get my conclusion on whether server-side tracking is the future for complete data collection.

Server side tracking vs client side tracking

In simple terms, a distinction can be made between server side tracking and client side tracking. For the sake of clarity, I would like to limit myself to these two alternatives in this article. 

What is client side tracking?

With client-side tracking, user data is collected directly in the visitor's browser. This means that the tracking code (e.g. from Google Analytics or Facebook Pixel) is embedded in the HTML of the website and is executed by the browser when the page is loaded. Interactions such as page views, clicks and scrolling behavior are recorded.

The collected data is then sent to the tracking tools' servers, where it is analyzed and used to optimize marketing campaigns or improve the user experience.

What is server side tracking?

With server side tracking, on the other hand, the tracking data is processed directly from the website server and forwarded to the analysis tool - not via the user's browser. Here, the tracking script is also embedded on the website, but the processing takes place on an intermediate server before the data is forwarded to analysis platforms such as Google Analytics, Facebook or others.

Why is server side tracking becoming more and more important?

Server side tracking is gaining in importance as it compensates for many of the disadvantages of client side tracking and thus represents a reliable alternative that better meets the current challenges in data protection and data quality.

While JavaScript tags are executed in the user's browser and third-party cookies are used in client-side tracking, the data is collected and processed directly by the website's server in server-side tracking. In this way, adblockers and anti-tracking measures, such as Intelligent Tracking Prevention (ITP) in iOS and Firefox browsers, remain ineffective as they cannot influence server-side data collection. Server-side tracking therefore ensures that data is collected comprehensively even under difficult conditions.

Another advantage is better control over data security and data protection. As fewer third-party providers are involved in server-side tracking, website operators retain more control. Sensitive data can be filtered or anonymized before it is forwarded to analysis tools, which meets the data protection requirements of the GDPR.

In addition to the higher data quality, server side tracking also offers a performance advantage. As the tracking scripts are not executed directly in the user's browser, the loading speed of the website is improved. This means that users have a faster and smoother experience, which in turn can have a positive effect on key figures such as the conversion rate or dwell time.

These advantages make server side tracking an important solution for companies that depend on reliable user data despite growing restrictions in client side tracking.

What are the advantages of server side tracking?

Server-side tracking has been around since the 90s, but client-side tracking has become more popular so far. Let's take a look at the reasons.

Client-side tracking advantages and disadvantages

Advantages:

1. Simple implementation: Tracking scripts can be integrated directly into the HTML of the website.
2. Flexibility: Changes and adjustments to tracking can be made quickly and without server intervention.
3. Lower costs: No additional servers required; usually faster and cheaper to launch.
4. Wide distribution and compatibility: Client side tracking is the most frequently used method, which is why many tools are optimized for it.

Disadvantages:

1. Vulnerable to adblockers and privacy settings: Many users block tracking codes via adblockers or browser settings.
2. Reduced data security: Sensitive user data can be intercepted more easily as it is processed directly in the browser.
3. Performance loss: Too many tracking scripts can slow down the loading time of the website.
4. Limited data quality: Higher risk of manipulation by bots or incorrect data transfers.

Advantages and disadvantages of server-side tracking

Advantages:

1. Greater data security: Data is processed on the server side, which offers protection against attacks and manipulation.
2. Less data loss: Bypasses adblockers and browser-side privacy settings, enabling more reliable data collection.
3. Better website performance: As the tracking code is processed on the server side, the browser and loading times are less affected.
4. Higher data quality: The data is more reliable and less susceptible to manipulation.

Disadvantages:

1. Higher implementation costs: Setting up and maintaining your own server involves higher costs.
2. More complex implementation: Setup requires more technical expertise and can be more complicated than client-side tracking.
3. Limited flexibility: Changes in tracking usually require adjustments to the server, which is slower and more complex.
4. Reduced tool compatibility: Some analysis tools are primarily designed for client-side tracking, which can make integration more difficult.

Data protection and GDPR for server side tracking

A key advantage of server side tracking is that it shifts the data processing to the server and therefore offers more control over the data flow. This structure can help to better fulfill the data protection requirements of the GDPR, as less personal data is processed in the user's browser. For example, sensitive data can be filtered or anonymized on the server before it is forwarded to third-party tools to ensure that no personal information is transmitted without a legal basis.

However, it is important to note that simply moving tracking to the server side does not automatically mean that it is compliant with data protection regulations. Companies must continue to ensure that they obtain user consent before collecting personal data or anonymize the data in such a way that it cannot be traced back to individual persons. The use of first-party data and the avoidance of third-party cookies are also methods that can help to make data collection GDPR-compliant.

Hybrid tracking setup and server side tagging

Another tracking option is to combine the two tracking options, which results in a hybrid setup and can be the best setup in some cases.

The hybrid tracking setup combines the advantages of client-side and server-side tracking and thus offers a flexible and reliable solution for data collection. In such a setup, certain data is recorded directly in the browser (client-side) in order to track real-time interactions such as clicks or scrolls immediately.

However, other data protection-critical or performance-relevant information is processed on the server. Server-side tagging plays an important role here: instead of executing tracking codes (tags) directly in the browser, they are managed on a special tag manager server.

This server-side tag manager receives the data and forwards it to the analysis or marketing tools in a controlled and secure manner. This allows sensitive data to be better protected and ad blockers and tracking protection functions to be bypassed.

This combination enables more accurate data collection and improved website performance, as fewer tracking codes need to be loaded in the browser. Hybrid tracking is ideal for companies that rely on both high data quality and the flexibility of client-side tracking.

1. Google Tag Manager (server-side): Server-side variant of GTM, enables tags to be hosted and managed on a dedicated server, improves website performance and supports GDPR compliance.
2. Stape.ioSpecialized platform for server-side tracking, especially for integration with Google Tag Manager. Easy to set up, optimizes data quality, reduces the impact of ad blockers and is GDPR compliant.
3. Piwik PROAnalytics platform with a focus on data protection, supports server-side tracking and can be hosted on-premise or in a private cloud, ideal for GDPR-compliant data processing.
4. Matomo (formerly Piwik): Open source alternative to Google Analytics, enables hosting on own servers for full data control, suitable for companies with high data protection requirements.
5. Segment (with server side tagging): Customer Data Platform, centralizes user data and supports server-side tagging, improves GDPR compliance and data quality.
6. Heap Analytics: Offers server-side implementation with "automatic event tracking" (Auto Track), ideal for data-driven companies looking for detailed analysis and high data quality.
7. Adobe Analytics (via server side tagging): Extensive tracking options, combinable with Adobe Launch, for larger companies with GDPR-compliant tracking requirements.
8. TealiumComprehensive tag management system with server-side tracking solutions, supports first-party data strategies and offers numerous integrations for data protection-conscious companies.

Conclusion: Server side tracking is gaining relevance

Due to recent challenges, server side tracking is currently experiencing a renaissance. Online marketers need some customer data for successful campaigns and this will no longer be available via the client side in the future. For this reason, online retailers should be ready to upgrade to server side tracking. If you are reaching your limits with tracking, we can help you with the right setup so that you can regain access to all significant data.

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