In August 2011 TechCrunch reported that Apple will be phasing out access to the unique device identifier or UDID on iOS devices such as iPhones and iPads.  The Apple developer documentation cited in the report mentioned that UDID has been "deprecated in iOS 5".  This caused some concern in the mobile analytics community because vendors commonly use the UDID to identify visitors.


We believe that this is an early warning from Apple to give developers time to come up with alternatives.  We believe the feature will be marked as deprecated in iOS 5 but will still be available for use for a reasonable amount of time.  This phased approach to deprecation would be consistent with Apple's documentation on deprecated API usage, and also consistent with Apple's approach historically.


Webtrends Visitor Id

The first time a Webtrends-enabled app is run, a visitor id is established and written to application-specific persistent storage.  Thereafter the app uses the stored visitor id.  By default the Webtrends SDK for iOS uses a hashed version of the UDID for the visitor id.  You can already configure the Webtrends SDK for iOS to use a randomly generated value for the visitor id instead of the UDID.  This is done by adding the following lines to the Webtrends.plist file:



After making this configuration change, the updated app should be posted to the App Store.  Users who download the new version will then be tracked using the random vistor id.



In light of this announcement from Apple, Webtrends will modify its Mobile SDK for iOS.  The new version of the SDK will default to the randomly generated visitor id.  Until then, customers can achieve this result by using the above mentioned configuration setting.



  • Apple Sneaks A Big Change Into iOS 5: Phasing Out Developer Access To The UDID

  • Using SDK-Based Development - Deprecated API Usage

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