A unique identifier for a bundle.
- iOS 2.0+
- macOS 10.0+
- tvOS 9.0+
- watchOS 2.0+
- Core Foundation
- Bundle identifier
A bundle ID uniquely identifies a single app throughout the system. The bundle ID string must contain only alphanumeric characters (A-Z, a-z, and 0-9), hyphens (-), and periods (.). The string should be in reverse-DNS format. Bundle IDs are case sensitive.
The operating system uses the bundle ID to identify the app for which a given preference applies. Similarly, Launch Services uses the bundle ID to locate an app capable of opening a particular file. The bundle ID also validates an app’s signature.
watchOS Apps with Companion iOS App Considerations
For watchOS apps that have a companion iOS app in the same project, the embedded WatchKit app and WatchKit extension targets must have the same bundle ID prefix as the iOS app. The WatchKit app must have the format
[Bundle ID].watchkitapp, and the WatchKit extension must have the format