Property list (plist) files are Apple’s native configuration format, used throughout iOS and macOS for app settings, system preferences, and metadata. Every iOS app has an Info.plist that defines its bundle identifier, permissions, supported orientations, and URL schemes. Understanding plists is essential for Apple platform development.
Plist Formats: XML and Binary
Plists come in two serialization formats: XML (human-readable) and binary (compact and fast). Xcode typically shows the property list editor view, hiding the underlying format. The XML format is useful for debugging and version control, while binary is used in production for performance.
Common Plist Use Cases
Info.plist contains app metadata and permissions declarations. Entitlements plists define app capabilities like push notifications and iCloud access. UserDefaults stores user preferences as a plist. Launch agents and daemons on macOS use plists for service configuration.
Plist Data Types
Plists support strings, numbers (integer and float), booleans, dates, data (binary), arrays, and dictionaries. This type system is richer than JSON (which lacks dates and binary data) but less flexible than YAML. The limited type set keeps plists simple and unambiguous.
Common Pitfalls
The most common plist mistake is forgetting to add required Info.plist keys. Missing privacy usage descriptions (NSCameraUsageDescription, NSPhotoLibraryUsageDescription) cause App Store rejection. Incorrect URL scheme definitions break deep linking. These issues are often caught only during testing or review.
Viewing Plists on the Go
ParseLab for iOS can open and display plist files with proper formatting and type visualization, making it easy to inspect app configurations, debug entitlements, and review Info.plist contents directly from your iPhone.