Server-side tagging vs. client-side tagging explained

Imagine your Web site is a store. In that store, visitors walk around, look at products and sometimes put something in their basket. Just as a retailer wants to know what's going on in his store, you as a Web site owner want to know how visitors are using your site. But how do you keep track of that? That's where "cameras" come into play. Let's look at two different ways: client-side tagging and server-side tagging.

Client-side tagging (third-party cameras in your store)

With client-side tagging, cameras from different companies, such as Google, Facebook and others, hang in your store. These cameras all separately watch what your customers are doing:

👀 For example, Google's camera looks at how long someone is in your store and which shelves are being looked at.
👁️ Facebook's camera registers which products are of interest for ads.
📹 O ther cameras might track which buttons are clicked or when a purchase is made.

What happens with client-side tagging?

All these cameras send their own images (data) directly to their own systems. This means your store is full of cameras from all sorts of companies, all of which are watching and collecting data.

Disadvantages:

📉 Adblockers and privacy settings may block some of these cameras, causing you to miss important information.
🐢 S lower: All those separate systems have to collect and process data separately, which can make your website slower.
👮 Privacy risks: You have less control over what data is shared and exactly what happens to that data.

Server-side tagging (one private camera in your store)

With server-side tagging, you hang one of your own cameras in your store. This camera records what happens: which products are viewed, which buttons are clicked, and when a purchase is made.

What happens with server-side tagging?

Instead of Google and Facebook putting up their own cameras, you yourself tell those systems what your camera has seen. So you control exactly what data you share with them. This means your store doesn't have a proliferation of third-party cameras.

Advantages:

🛡️ Not blocked by adblockers: Because it is your own camera, adblockers and privacy filters (such as Apple's ITP) cannot simply block it.
⚡ Faster: You send data only once to your server, which then distributes it to the appropriate systems.
🔒 More control: You control what data is sent and to whom.

Summary:

Client-side tagging: Third parties (such as Google and Facebook) hang their own cameras in your store and watch. This is slower and can be blocked by adblockers.
Server-side tagging: You hang up one camera of your own and tell third parties yourself what you see. This is faster, harder to block and gives you more control over the data.

So server-side tagging is a smarter, more efficient way to track what's happening in your store without relying on all those external "eyes."