Server-Side Tagging with Google Tag Manager

In this in-depth blog post, we are dealing with server-side Tag Manager (also called "Tag Manager Server-Side") and in particular with the comprehensive product available from Google. Among other things, we aim to provide a thorough explanation of what this technology is, the functions a server-side tag manager offers, how it operates, and how it stands apart from classic tag managers.

What is a "Tag Manager Server Side"?

Simply put, a server-side tag manager is used to receive data in a certain form, possibly manipulate it, and then forward it to a third party.

While this might sound trivial, it plays a significant role. Normally, the tags loaded from your website collect data and send this information directly from the browser to the respective third party. For instance, data collected by Google Analytics would go directly to Google. In server-side tagging, a separate server is used as an intermediate station (also called a proxy), which receives the collected data, processes it if necessary, and then sends it on to the tracking providers.

The server-side tag manager, despite its similar name, is not comparable to a client-side tag manager. The latter is only used to play out the tracking scripts ("tags") according to the trigger configuration. With server-side tagging, on the other hand, it's all about receiving information from users and passing it on to third parties.

How can You use a "GTM server-side"?

Just like with the client-side tag manager, there's also a product from Google that we recommend. Essentially, using server-side GTM (Google Tag Manager) has three major benefits: First, you can use some tracking services, such as Google Analytics, without the user's consent since no personally identifiable data is forwarded to Google. Second, you can bypass browser tracking preventions. These can limit or even block tracking in the browser even with full consent, which can indeed have negative effects. For example, users may be less easily recognized, resulting in a higher number of "new users" erroneously identified. Third, Google products can be self-hosted, such as a Web GTM Script or Google Analytics Scripts, thereby improving the PageSpeed scores and the Google Core Web Vitals which in turn enhances the user experience on your website.

Does the "GTM server-side" replace the classic Client-GTM?

No, it doesn't. Although they have similar-sounding names, their functions differ fundamentally. While the server-side GTM is used to receive user data, possibly manipulate it, and then pass it on to third parties, the classic Web-GTM (or also client-side GTM) is used to play out tags on the website.

What is the Cost of a "GTM server-side"?

In itself, the server-side Google Tag Manager is a free product for which no license fees are incurred. Possible costs only arise from the operation of your own server/server network.

Does the Server have to be rented in the Google Cloud?

The preferred implementation option is an App Engine service in the Google Cloud. In this way, Google takes care of the provision, maintenance, backup, and scaling of the server instances. Alternatively, the tagging server can be installed in a different environment using a provided Docker image.

Don't hesitate to arrange a non-binding initial consultation with us. We check your current web analytics and online marketing configuration for free and provide you with an individual implementation plan for a server tag manager.