Why server-side tagging in Google Tag Manager is a game changer

Google introduces server-side tagging within its ecosystem. While server-side tag management isn’t new, Google’s introduction of it makes it more accessible thanks to lower implementation and setup costs. This update is a milestone for (Google) analytics users, which is why the change is creating some buzz. Find out why this might be a game changer for you as well.

To understand the significance of server-side tagging via Google Tag Manager and Google Cloud, we need to breakdown a few other questions.

What is server-side tagging

There are two ways to collect data: client-side and server-side. Both with their own benefits and restrictions:

Comparison client-side and server-side tagging

Client-side tag management

Is the most common and popular way to trigger tags (= pieces of code attached to a pixel) that allow you to track user information from a web page. In this approach, the user’s browser - also known as a client - sends data directly to a third-party server via a JavaScript request. To achieve this, marketers often use a tag management system (TMS), which can trigger these tracking pixels based on a set of rules. Thanks to a TMS, you can release new tags without the interference of development.

Server-side tag management

Server-side tag management basically does the same thing, but adds an extra layer of server-side tag management to the process. Instead of running the tracking requests directly from the client-side (or browser) to third-party servers, it runs them through a first-party server or back-end environment first. This means that the data runs through your own server before you send it to an external receiver like Google Analytics, Facebook or Bing.

What are the befits of server-side tagging

Because the requests are run through your own server, you have more control and capabilities to transform and enrich your data. This gives you a lot of new possibilities:

Faster site experiences

Page speed and website performance is one of the more obvious reasons to onboard server-side tagging. Optimizing the page load time of your website can demand a lot of effort. More often than not, third-party code and JavaScript execution time is one of the biggest bottlenecks in terms of page load time.

Advantages website speed server-side tagging

Server-side tagging can reduce this JavaScript execution time significantly. As a result, your website will load faster, the user experience improves and the conversion rate rises.

Secured customer data

With server-side tagging, you place third-party tags in your own secure server container. This gives you more control over the data that’s captured and who gets to see it. You gain visibility into what data the tags are collecting and where that information is being sent to. This allows you, for example, to encrypt sensitive data or to prevent personally identifiable information (PII) from being sent to external parties. Information that, if it was sent straight from your website to a third-party server, would in full be available to an external party.

Better data quality without ITP and AdBlockers

Web browsers like Safari and Mozilla have released a range of updates, like Intelligent Tracking Prevention (ITP), that work against tracking technologies by blocking third-party cookies. This means that, by default, no advertiser or website is able to follow you around the internet using the commonplace tracking technology. A similar situation presents itself with Adblockers.

Through server-side tagging, ITP and AdBlockers won’t be able to detect and block tracking behavior, allowing you to track more users. More data means that ultimately the quality of this data will increase as well.

Don’t forget, though, that with these new capabilities you will gain some extra responsibilities. Obviously, privacy regulations like GDPR maintain applicable. You still need user consent to gather and store their data. Server-side tagging doesn’t change that fact one bit!

More than ever it is your responsibility to respect the privacy of your users and to follow the regulations, not only by letter but also by heart

Still, we can’t really shake the feeling that this update is - at least in part – Google’s reaction to the recent ITP updates. In the end, Google is for a large part an advertising business and technologies will continue to evolve for maximum impact. More than ever it is your responsibility to respect the privacy of your users and to follow the regulations, not only by letter but also by heart.

Enriched data

Contrary to the previous point, you can also enrich the incoming data with relevant information before you send it to an external party. For example, you can add product information, business context, lead quality score, weather information or customer resource management (CRM) data to the mix. On top of that you can also send the data in different directions, like your own data warehouse for example.

These new capabilities call for some new priorities. We recommend defining those priorities based on feasibility and business value. To have a better understanding of the feasibility of this implementation, you need to have an understanding of how you implement server-side tagging.

How to implement server-side tagging

The first steps in implementing server-side tagging are “relatively” easy. There is already a lot of documentation available online. We recommend the step-by-step guidelines of Simo Ahava:

We used these guidelines to implement of a basic Universal Analytics tracking ourselves. Simo Ahava is the master when it comes to Google Tag Manager (GTM) guidelines, so we won’t waste any of your (and our) time with a less thorough guide. We will, however, add a few of our personal thoughts, based on our experience:

  • It took me a less than an hour to implement server-side tagging, but it took me a few years to do this within the hour.”
    - Thomas Danniau, solution lead at The Reference

    In other words: you need experience with Google Tag Manager, Google Analytics, Google Cloud and web technology in general. For this implementation, Development and IT knowledge is required, especially if you want to have a setup up and running for a live environment.
  • At this moment, the feature is in beta and it certainly isn’t a plug-and-play setup. There are a few things that are unpredictable or could go wrong. Not only from Google’s end but also (and even more likely) from your end. A misstep is easily made and debugging any issues will require expertise. Before you use server-side tracking for business-critical aspects, start with an acceptance/test environment, do a lot of testing, monitor and evaluate incoming data, and so on. You also need to be familiar with standard development and IT best practices in terms of security, maintenance and performance. Best practices where, traditionally, a marketer is less educated or persistent in.

If you want to go beyond the innovation and curiosity phase, determine the right benefits and use case for your business

  • Server-side tagging won’t replace all your client-side tags. Most of the Google tags are ready to be switched to server-side tags, but other vendors' tags aren’t (yet). Make an inventory of the existing tags and make sure your expectations are aligned with the reality.
  • For our test case we used a third-party domain. By default the tracking is hosted on a Google Cloud environment with an URL like gtm-* For a live website, we recommend this endpoint would be mapped with a custom subdomain within the same top-level domain (like  By using a subdomain, the requests are considered to be first party, which will have a significant impact on how cookies can be read and written.
  • The server-side Universal Analytics implementation is just the tip of the iceberg. As mentioned before, new doors will open and opportunities will arise. If you want to go beyond the innovation and curiosity phase, determine the right benefits and use case for your business.

Conclusion: why this is a game changer?

Server-side tracking has been around since the beginning of web analytics. Vendors like Tealium and Segment have been giving you the option to choose your preferred approach for a while already. So, why is this only now considered a game changer? And why is this update to Google’s services so important for the months and years to come?

  • The game will change because there are different rules. Certain limitations are eliminated, which means more options for you. Even though these options where available already via other vendors, via Google they are more accessible than ever.
  • Because Google Analytics is by far the market leader in terms of web analytics, it will probably set the bar for other vendors and advertisers. Some of those vendors will have a very hard time keeping up with the new standards. This is especially applicable for advertisers that are mainly depending on cookie technology. Eventually, these new standards will likely lead to less players.
  • Different rules will require different skills and talents. With a thorough understanding of what is going on behind the scenes, you will benefit most from the new flexibility that server-side tracking offers. It is a trend that digital marketing is becoming more technical. These new capabilities emphasize this trend even more.

Want to implement server-side tracking for your website?

Our digital marketing experts have the right know-how and experience to help you implement this new feature of Google Tag Manager and Google Cloud. Find out how we can help you get this tracking methodology up and running.

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The Reference is nothing without its customers. Melexis is the stock market-listed global player in the semi-conductor and sensors industry for whom we facilitated future company growth by updating the brand, building the completely new corporate website and giving shape to the use of online channels. Read more about this client.