9 Reasons to Use Server-Side Tagging Over Client-Side Tagging
You often encounter Server-side and client-side tagging in online marketing and web analytics. Recently, most people have been advocating for server-side tagging over client-side tagging. Why?
Marketing is all about understanding consumer behaviors. However, you can only achieve this through effective data collection and tracking techniques.
In this article, I will explain in detail what tagging is, its importance in data collection & tracking, differentiate between server-side and client-side tagging, and illustrate why to use server-side tagging over client-side tagging.
What is Tagging?
Tagging simply means adding tags (small pieces of code) to a website. Such tags are designed to collect data about user interactions, send information to third-party analytics tools, or track events.

These tags can be used to achieve the following:
- Web analytics: You can track user behavior on a website on metrics such as form submissions, clicks, or page views.
- Personalization: You can use these tags to gather the information that personalizes user experience based on behavior or individual preferences.
- Remarketing: These tags can collect data that creates audiences that marketers can target for remarketing.
- Conversion tracking: The tags can monitor events indicating a conversion, like filing a lead form or a successful purchase.
You can add these tags (code snippets) on the server or client sides.
Client-side tagging
Client-side tagging is when we add the tags to the client side. There will be a single container residing on the app or website. This tag will contain all the tags, variables, triggers, and code that measures user interaction.
The container will be activated and load the relevant tags once a user visits a page. An action from a user will trigger a tag that then dispatches the event data into one or more HTTP requests from the browser.

Server-side tagging
Server-side tagging is where tags are processed on the server. This tagging approach has two containers:
- Server container that is located in a cloud environment
- Web container located in the app/website
The web container has tags that monitor and dispatch information about user interactions. This container then generates events as HTTP requests. On the other hand, the server container accepts requests from the web container.
Most marketers are now moving to server-side tagging. Does it mean that client-side tagging is no longer working?
These are some of the reasons why most people are moving to server-side tagging:
Performance Improvement

Server-side tagging reduces the amount of code being executed, which leads to improved speed and performance. The browser maps each event to a single or multiple HTTP request on the client-side tagging. The client can end up sending multiple similar requests, which end up overloading client resources.
On the other hand, in server-side tagging, a client generates only one HTTP request per event. This HTTP request is then sent to the server container, which generates and dispatches server-specific requests. As a result, there are few HTTP requests and less code executed, resulting in increased speed.
Privacy, Safety, and Security
When using client-side tagging, it is hard to control which data is shared between the browser and third parties. Depending on how your application shares information, there is a risk that personally identifiable information will be shared in HTTP requests.
On the other hand, server-side tagging grants you control over the nature of data to be shared with third parties. The server container lets you remove any personally identifiable information before passing it to marketing platforms. This approach ensures that you only share relevant data and what complies with data regulations that are in place.
You can also set a first-party context in your server container. Ideally, all the website data and cookies will stay in your domain, making it hard for vendors to access third-party cookies.
Accuracy

All server-side processes happen outside the browser. This makes it easy to ensure the validity and consistency of data that you send to the vendor endpoints. For instance, client-side processors like devices and browsers might introduce inconsistencies in event data. However, server-side tags can perfectly fix those to ensure consistency.
Server-side tagging is also a perfect solution to reduce data loss risk. When tagging is done on the server side, it will validate the data and ensure that it meets all the acceptable standards set by the vendors. Server-side tagging also removes unnecessary/redundant data that the app/ browser might have inserted.
Ad Block Resistance

Businesses are expected to respect user preferences and privacy. However, some ad blockers can block tools unrelated to marketing. For instance, you may have cookies meant to improve user experience or web analytics to analyze user behavior.
With a custom domain and server-side implementation, you can pass such data without facing the wrath of ad blockers. This approach is considered first-party data; you no longer have to rely on third-party domains.
Better Campaign Management

Server-side tagging offers a stable data collection environment. This reduces discrepancies between different sources. As a result, as a marketer, you collect data accurately, track conversions, and get better insights into your marketing efforts.
You can also consolidate all your pixels and tags into a central location. It thus becomes easy to manage, implement, and update your analytics and marketing tags.
Control over User Inputs
Server-side tags give your application more control over user inputs. Such an application will sanitize and validate user inputs before it processes them. This approach is perfect when you want to prevent threats such as cross-site scripting (XSS) or SQL injections that may happen when users send malicious code for processing.
The technological world is ever-changing. Even though third-party cookies have been a thing for some time, they are now being phased out. Third-party cookies are generated and placed on the user’s device by another app/website rather than the one a user is visiting. Privacy concerns have been a huge debate recently, and the phasing out of third-party cookies has been fronted as one of the solutions.
Easy to Update and Patch

Updating server-side tags (code) is easy, as you only need a developer. The ease of updating server-side tags ensures that your tracking tools are always up-to-date and secure. You can also set your updates to be automatic when using server-side tags.
On the other hand, client-side tags demand that you manually update your browser or device. Updates on client-side tags are also vulnerable to blocking from browser extensions and ad blockers, which means updates might be blocked.
Scalability
Client-side tagging is less scalable than server-side tagging. This is because the former relies on the user’s browser to execute tags, which may overload or even slow down page loading times. Server-side tagging and tracking make it easy to handle large amounts of data. You can also adapt the tags as your application/website grows. Furthermore, server-side tags are not affected by ad blockers, leading to accurate data collection.
Limitations associated with server-side tagging
Despite the many advantages associated with server-side tagging, it also has the following limitations:
- Complex implementations: Server-side tagging may require tech-savvy people to implement. As such, you must modify server configurations that may require serious collaboration between developers and the IT team.
- Less tracking of user behavior: You may not have as much granular visibility into individual behavior when using server-side tagging as you are likely to get with client-side tagging.
- Dependent on developers: You may depend so much on developers to add tags (code snippets) to the server. On the other hand, you can implement client-side tagging using plugins even if you are not tech-savvy.
Server-side vs. Client-side Tagging
Feature | Server-side | Client-side |
---|---|---|
Location | Executes on the server side of an application | Executes on the client side/ browser |
Flexibility | Less flexible in tracking user interactions | Tracks all user interactions as they browse through different pages on a website/ application |
Responsiveness | Does not rely on client-side events or browser capabilities | Dependent on client-side events, browser capabilities, and user interactions |
Ad blockers | Tracking occurs on the server. As such, server-side tagging is not affected by ad blockers | Tracking scripts are executed on the client, making it susceptible to ad blockers |
Page load impact | It does not affect the page load | A lot of JavaScript is processed on the browser, which may result in slower loading speeds |
Data security | Marketers have control over the content that is sent to vendors | The possibility of exposing sensitive data to third parties is very high |
Best practices for implementing server-side

- Create a consistent data layer design: Create a clear, structured data layer that defines the information you should send to analytics platforms. The naming conventions within this data layer should also be consistent.
- Validate data: Create validation checks that ensure only valid data is processed and goes to the analytics server.
- Implement secure communication: Use protocols like HTTPS to send data between your server and analytics platforms. This ensures that no one will intercept and use your data to your disadvantage.
- Comply with privacy regulations: Data privacy has been a hot topic. Ensure that you comply with data regulations like GDPR and CCPA to be on the safe side. Also, ensure you get consent before tracking user activities and let them know how you will process their data.
- Monitor and log: You can set up various tools to track the performance of your server-side tags. You can also have logging tools that record relevant information and events for auditing purposes.
Conclusion
You now understand why server-side tagging is taking over client-side tagging in marketing and analytics. Even though the client-side is easier to implement, we have discovered that advantages such as being future-proof, economical, and ad block-resistant make most marketers prefer server-side tagging over client-side tagging. This approach also makes you to be in control as you can decide what to feed the algorithm.
Next, you may also explore some self-hosted open source web analytics platforms.