Alongside the release of iOS 16.1, Apple has also published the documentation for SKAd Network 4.0 for developers. This means that if all parties involved support SKAN 4.0 and the ad is served in a device with iOS 16.1 and above, Apple would send the new 4.0 information.

With the initial information shared by Apple at the WWDC conference in June, many were left with some doubts regarding the definitive functionality of the new postbacks this version presented. In this article, we are going to cover all the missing information everyone was waiting for. If you don’t know what this new version is about, you can check the article we posted explaining all the details.

Hierarchical Conversion Values

The main talking point of this new version was the hierarchical conversion values. Together with the introduction of the new coarse-grained conversion value, it shares some information at a lower threshold than the fine-grained conversion value. The postbacks window of attribution was completely redefined with 3 separate windows 0-2 days, 3-7 days and 8-35 days opposed to the single one from the versions 3.0 and below. With this new functionality, advertisers will have more visibility on post-install activity, including ROAS, user LTV, etc

The main question was about the delay timer of each window. With the release of the documentation, the doubts everyone had regarding the implementation can be now answered. 

The different postbacks registered during the window will be stored and sent as shown below, with a delay of 24-48 hours for the first postback and 24-144 hours for the second and third.


Nevertheless, Apple has also added a new method to lock conversion values and receive postbacks sooner. This means that if there is a conversion value defined with that method, this value will be locked and the random delay to send the postback will be initialized before the conversion window ends. This method is independent of all the different windows, and you can choose to use it in any of the conversion windows.


Having this functionality, advertisers will be able to receive the install postback after 24 hours if set up correctly, compared to the default 72 hours minimum without the method implemented. Smadex will be able to optimize the campaigns faster thanks to the Flexible Mapping tool and the decrease in the delays when using the method. 

Web to app 

One of the main new capabilities presented by SKAd Network 4.0 is the support for web-to-app campaigns. Apple will only allow click through attribution from clicks coming only from Safari browser. This answers the question about the possibility to have web to app in all browsers: for now, only in Safari. 

Smadex will be able to create specific web-to-app campaigns thanks to the browser targeting tool in order to target the optimal traffic needed to be attributed by Apple.

Hierarchical source identifiers

Finally, SKAN 4.0 introduced an update of the previous campaign identifier now called source identifier. This value will now be a four-digit value that can be used to map different information useful to better understand the performance of the campaigns, like the different creatives or their location. Resembling the other features, this information is going to be sent depending on the level of crowd anonymity. If you want to receive the 4 digits, some unknown threshold of installs per day has to be reached in order to receive the additional digits.

For advertisers, this new identifier will give even more data granularity on top of the information Smadex can already report thanks to the implemented tools. Having more insights to the campaign can lead to better optimization.

Smadex is already working towards supporting this new version of SKAd Network 4.0. Since the beginning, the company has been an early adopter to the new features in order to reach all the traffic available and lead the SKAN market. Thanks also to our Flexible Mapping Tool and our SKAd Network algorithm, it is possible to optimize our campaigns and improve performance overtime.

If you want to learn more about SKAd 4.0 and Smadex’s Flexible Mapping solution, make sure you check out: