Google Tag Manager (GTM) is a tool created by Google that allows you to manage and deploy tags on websites without having to interfere with the website’s source code. GTM allows online marketers and website administrators to easily and flexibly manage tags without having to go into the website code every time a tag needs to be added, changed or removed.
Client-side tagging
Until now, the vast majority of those using Google Tag Manager have used what is known as client-side tagging. In such a setup, a single container containing tags, rules and variables is placed in a site or application, and associated appropriate code to measure user interactions. In client-side tagging, a user visits a page, then the container is activated and loads the associated tags. When the user performs an action that triggers the tag, the event data is sent as at least 1 HTTP request from the browser or device to Google services or third parties such as advertising partners.
Server-side tagging
Server-side tagging in GTM is a more advanced technique. To use server-side tagging, it is necessary to integrate GTM with a server. This may require access to a specific server and programming skills. GTM allows server-side tag configuration management, which means you can enable, disable or customize tags without interfering with the site’s source code. Google Tag Manager on the server side uses two containers:
The web container stores only the tags necessary to monitor and send information about user interactions and generate events in the form of HTTP requests. The server container, on the other hand, accepts all HTTP requests from the web container. In the server container, processing rules are configured before the data is sent to Google services.
Why use GTM on the server side?
The server container acts as its own intermediate endpoint between the browser or device on which events are logged and external endpoints. An endpoint is simply a place on the network to which queries can be sent to access certain functions or data. It complements the web container by processing tasks that require significant resources and would normally be run in the browser as part of a client-side tagging setup. In addition, the server container offers the ability to monitor, verify and possibly modify data before it is sent to endpoints that are responsible for analytics or advertising functions.
Benefits of server-side tagging:
Performance optimization
Server-side tagging contributes to client performance by minimizing the length or amount of code that must be executed in a browser or application. With client-side tagging, each event must translate into at least one HTTP request, depending on the number of endpoints to which the event data is sent. As a result, the client can generate many very similar HTTP requests, which puts a significant strain on the device’s resources. With server-side tagging, the client only needs to generate 1 HTTP request per event, which is then forwarded to the server container. It is the server container that is responsible for generating and forwarding requests to specific providers. This results in improved site performance, as the client does much less work and sends fewer HTTP requests. To further speed up the process of loading pages, it is possible to load entire libraries and marketing resources by using a server-side tagging environment, as well as using the server as a content distribution network.
Protect the privacy of user data
When using client-side tagging, the user’s browser directly engages in communication with third parties (third parties), which can introduce difficulties in controlling the information shared. Depending on how a site or application processes user data, there is a risk that HTTP requests may include information that identifies user data. Server-side tagging, on the other hand, provides full control over the data shared with third parties. Before passing them on to marketing partners, server-side GTM gives you the option to remove any personally identifiable information about users from the server container. This ensures that only data that is necessary and compliant with privacy regulations is transferred.
Once the server container is properly configured for its own domain, all page data and cookies are managed directly from the server. This means that providers do not have access to third-party cookies. This allows us to implement stricter content security policies, as the browser communicates with fewer or no third-party domains, depending on the configuration.
More valuable data
In the context of client-side tagging, maintaining the integrity and correctness of data transmitted directly to vendor endpoints can be problematic. Server-side tagging provides an opportunity to maintain control over the data. With this method, we can minimize the risk of data loss by verifying the event data on the server side. We can also remove redundant or unnecessary data that may be added by a browser or application.
Disadvantages of server-side solution in GTM
GTM’s server-side configuration is much more advanced and complicated than the client-side version. It requires access to the server and also advanced technical knowledge. This can mean higher costs and a more difficult and complicated implementation. The use of server-side tagging can also put a strain on the server, especially when there is a lot of website traffic. Adequate server resources are required, which can incur additional costs. For sites hosted on third-party servers or shared hosting, access to the server may be limited or impossible, making it impossible to use a server-side solution.
In summary, GTM’s server-side tagging allows for more efficient management of tags, data, including privacy and site performance. However, this option is advanced and can be very complicated to implement, with additional costs. The choice between server-side and client-side tagging should therefore be carefully considered, taking into account the needs and goals of the individual project.
