Server-side tracking & server-side tagging: why it is becoming increasingly important

One of the most essential aspects of online marketing is the reliable tracking of user behaviour. Unfortunately, however, this process is frequently hampered by a wide variety of challenges. Server-side tracking offers a solution to some of these challenges. That’s why, in this post, I’d like to explain the pros and cons of server-side tracking in more detail and highlight the differences between it and client-side tracking (the most widely used method). At the end, I’ll give you my verdict on whether server-side tracking is the future for comprehensive data collection.

Server-side tracking vs client-side tracking

Put simply, 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 post.

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 website’s HTML and is executed by the browser when the page is loaded. Interactions such as page views, clicks and scrolling behaviour are recorded in the process.

The data collected is then sent to the tracking tools’ servers, where it is analysed and used to optimise 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 on the website’s server and forwarded to the analytics tool – not via the user’s browser. Here, the tracking script is also embedded on the website, but the processing takes place on an intermediary server before the data is passed on to analytics platforms such as Google Analytics, Facebook or others.

Why is server-side tracking becoming increasingly important?

Server-side tracking is becoming increasingly important, as it overcomes many of the drawbacks of client-side tracking and thus offers a reliable alternative that is better suited to the current challenges in data protection and data quality.

Whilst client-side tracking involves executing JavaScript tags in the user’s browser and using third-party cookies, server-side tracking involves the data being collected and processed directly by the website’s server. In this way, ad blockers and anti-tracking measures, such as Intelligent Tracking Prevention (ITP) in iOS and Firefox browsers, are rendered ineffective, as they cannot influence server-side data collection. Server-side tracking therefore ensures that data is comprehensively collected even under challenging conditions.

Another advantage is greater control over data security and data protection. As server-side tracking involves fewer third-party providers in the data collection process, website operators retain more control. Sensitive data can be filtered or anonymised before being forwarded to analytics tools, thereby meeting the data protection requirements of the GDPR.

As well as providing higher data quality, server-side tracking also offers a performance benefit. As the tracking scripts are not executed directly in the user’s browser, the website’s loading speed improves. This means that users enjoy a faster and smoother experience, which in turn can have a positive impact on metrics such as the conversion rate or the time spent on the site.

These advantages make server-side tracking an important solution for businesses that rely on reliable user data despite growing restrictions on client-side tracking.

What are the benefits of server-side tracking?

Server-side tracking has been around since the 1990s, but client-side tracking has tended to become more widespread up to now. Let’s take a look at the reasons why.

Client-side tracking: advantages and disadvantages

Advantages:

1. Easy to implement: Tracking scripts can be embedded directly into the website’s HTML.
2. Flexibility: Changes and adjustments to the tracking system can be made quickly and without the need for server intervention.
3. Lower costs: No additional servers required; usually quicker and more cost-effective to get started.
4. Widespread use and compatibility: Client-side tracking is the most commonly used method, which is why many tools are optimised for it.

Disadvantages:

1. Vulnerable to ad blockers and privacy settings: Many users block tracking codes using ad blockers 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 website’s loading time.
4. Limited data quality: Higher risk of manipulation by bots or faulty data transfers.

Server-side tracking: advantages and disadvantages

Advantages:

1. Greater data security: Data is processed on the server, which provides protection against attacks and tampering.
2. Less data loss: Bypasses ad blockers and browser-based privacy settings, enabling more reliable data collection.
3. Improved website performance: As the tracking code is processed on the server side, there is less strain on browsers and page load times are reduced.
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: Setting it up requires more technical expertise and can be more complicated than client-side tracking.
3. Limited flexibility: Changes to tracking usually require adjustments to the server, which is slower and more labour-intensive.
4. Reduced tool compatibility: Some analytics tools are primarily designed for client-side tracking, which can make integration more difficult.

Data Protection and the GDPR in Server-Side Tracking

A key advantage of server-side tracking is that it shifts data processing to the server, thereby offering greater control over the flow of data. This structure can help to better meet 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 anonymised on the server before being forwarded to third-party tools, to ensure that no personal information is transferred without a legal basis.

It is important to note, however, that simply shifting tracking to the server side does not, in itself, automatically ensure compliance with data protection regulations. Companies must continue to ensure that they obtain users’ consent before collecting personal data, or anonymise the data in such a way that it does not allow any conclusions to be drawn about individual persons. The use of first-party data and the avoidance of third-party cookies are also methods that can help ensure data collection complies with the GDPR.

Hybrid tracking setup and server-side tagging

Another option for tracking is to combine the two tracking methods; this results in a hybrid setup and may, in some cases, be the best option.

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

Other information, however – such as data subject to privacy concerns or that is relevant to performance – is processed on the server. Server-side tagging plays an important role here: rather than executing tracking codes (tags) directly in the browser, they are managed on a dedicated tag manager server.

This server-side tag manager receives the data and forwards it to analytics or marketing tools in a controlled and secure manner. This provides better protection for sensitive data and enables ad blockers and tracking protection features 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 businesses that prioritise both high data quality and the flexibility of client-side tracking.

1. Google Tag Manager (Server-Side): A server-side version of GTM that enables tags to be hosted and managed on a dedicated server, improves website performance and supports GDPR compliance.
2. Stape.io: A specialised platform for server-side tracking, particularly designed for integration with Google Tag Manager. It is easy to set up, optimises data quality, reduces the impact of ad blockers and is GDPR-compliant.
3. Piwik PRO: An analytics platform with a focus on data protection; it supports server-side tracking and can be hosted on-premises or in a private cloud, making it ideal for GDPR-compliant data processing.
4. Matomo (formerly Piwik): an open-source alternative to Google Analytics, which allows hosting on your own servers for full control over data, and is suitable for organisations with high data protection requirements.
5. Segment (with server-side tagging): Customer Data Platform, centralises user data and supports server-side tagging, improving GDPR compliance and data quality.
6. Heap Analytics: Offers server-side implementation with ‘automatic event tracking’ (Auto Track), ideal for data-driven organisations seeking detailed analytics and high data quality.
7. Adobe Analytics (using server-side tagging): Comprehensive tracking options, which can be combined with Adobe Launch, for larger organisations with GDPR-compliant tracking requirements.
8. Tealium: A comprehensive tag management system with server-side tracking solutions, which supports first-party data strategies and offers numerous integrations for organisations that prioritise data protection.

Conclusion: Server-side tracking is becoming increasingly important

Due to recent challenges, server-side tracking is currently experiencing a resurgence. Online marketers need certain customer data to run successful campaigns, and in future this data will no longer be available via the client side. For this reason, online retailers should be prepared to switch to server-side tracking. If you’re finding yourself reaching the limits of your tracking capabilities, we can help you set things up correctly so that you regain access to all the relevant data.

Frequently Asked Questions