Server to server tracking, often shortened to S2S, is a method of sending data directly between two servers without relying on a browser or an app based tracking request. In mobile marketing, S2S is most commonly used by app owners to share event data with mobile measurement partners in a secure, controlled, and privacy conscious way.
S2S has become increasingly important as privacy rules evolve and as advertisers look for ways to measure conversions without depending on cookies or large SDK integrations.
Server to server tracking moves the responsibility of sending data away from the user’s device and onto the advertiser’s backend. When a user clicks an ad or creates an impression, the ad platform generates a unique identifier such as a click ID. The app or site stores that identifier until a conversion occurs.
Once the user completes the action, the advertiser’s server sends the click ID and the event information directly to the measurement partner. If the identifiers match, the attribution system can confirm the conversion.
S2S plays a similar role to third party cookies and in app SDK tracking, but it avoids many of the limitations those systems face. It helps marketers maintain visibility even when browsers block tracking or when apps face restrictions on data sharing.
Server to server tracking gives advertisers greater control over the data they collect and the data they choose to share. Instead of relying on a chain of SDKs inside the app, the advertiser uses their own secure server to send events to an attribution partner.
This creates several advantages:
Greater stability
Data does not depend on the user’s device or browser environment. This reduces the risk of lost events.
More control of sensitive data
Advertisers decide exactly which data points are transmitted. They can include valuable signals or exclude fields that must remain private.
Better resilience to privacy changes
Many privacy restrictions target client side tracking. S2S bypasses these constraints and keeps measurement working even when device level tracking is limited.
Cleaner and simpler integrations
Instead of installing multiple SDKs, advertisers can forward data from a single backend. This reduces app weight and lowers the chance of crashes or errors.
Mobile apps often rely on SDKs to track user behavior. These SDKs collect events like installs, sessions, or purchases and send them to various partners. Over time, apps can accumulate many SDKs: analytics, attribution, ad networks, crash reporting, and more.
Each SDK introduces more complexity. They increase app size, slow down performance, and create more potential for malfunction or postback abuse.
Server to server tracking avoids these problems. App owners can use a lightweight implementation for collecting user events and send those events through their own backend. From there, the server sends the final event to partners. This makes the app faster, safer, and easier to maintain.
Smaller and faster apps
Removing multiple SDKs reduces app size and improves performance for users.
Easier compliance
Centralized control of data makes it easier to implement consent rules and privacy frameworks.
Reduced fraud exposure
Server to server communication is less vulnerable to manipulation that commonly affects client side tracking.
Flexible event control
Developers can modify or expand the event structure without waiting for SDK updates.
Not always. Some apps keep a minimal SDK for essential functions and then supplement it with server to server tracking for reliability and control.
Yes. Sending data from one secure server to another reduces exposure to tampering and removes dependence on browser tracking.
No. Since it does not rely on third party cookies or client side storage, it continues to function when browsers block tracking.
Yes. The method applies to any environment where a server can send validated data to another server.
If implemented correctly, attribution partners can use S2S events the same way they use SDK based events.