Asset Catalog Format Reference: App Icon Type

The source images for the different sizes and resolutions of your iOS and watchOS app icons.

Extension

.appiconset

Folder Contents

.png files for the icons.

Contents.json File (Required)

Metadata and attributes for the individual icon files (Table 6-1).

**Table 6-1**App icon tags
Key	Type	Description
`info`	Dictionary	Metadata for the author and format version of the asset catalog.
`author`	String	Use your bundle ID.
`version`	Number	The format version of the asset catalog. Use `1`.
`properties`	Dictionary	Properties associated with the app icon. `properties` is an optional key.
`pre-rendered`	Boolean	Backward compatibility for iOS 6.0 indicating if the icon includes the mask and shine effect. `pre-rendered` is an optional key.
`images`	Array	Each element identifies one variant of the icon.
`filename`	String	The name of the `.png` file containing the image.
`display-gamut`	Slot component	The color gamut of the device display. For the values, see display-gamut in Image Set Type.
`idiom`	Slot Component	The idiom of the icon. For the values, see idiom in Image Set Type.
`size`	Slot Component	One of the sizes that matches the idiom for the icon. If the size is not valid, the image is ignored. For the values, see size below.
`scale`	Slot Component	The scale of the icon. For the values, see scale in Image Set Type.
`subtype`	Slot Component	The scale of the icon. For the values, see scale in Image Set Type.
`role`	Slot Component	The role of the icon in a watch app. For the values, see role below.
`unassigned`	Boolean	Used by Xcode.
`matching-style`	Enum	The type of matching for the system to use to find the referenced file. The only valid value is `fully-qualified-name`.

Values for Enumerated Tags

display-gamut

See display-gamut in Image Set Type.

idiom

See idiom in Image Set Type.

size

The size of the app icon in points. Also see Points Versus Pixels (Table 6-2).

**Table 6-2**`size` values
Value	Description
`16x16`	An OS X icon.
`20x20`	An iPhone or iPad notification icon.
`24x24`	A 38mm Apple Watch notification center icon.
`27.5x27.5`	A 42mm Apple Watch notification center icon.
`29x29`	An iPhone or iPad settings icon for iOS 7 or later. An Apple Watch companion settings icon.
`32x32`	An OS X icon.
`40x40`	An iPhone or iPad Spotlight search results icon on iOS 7 or later. The main Apple Watch app icon.
`44x44`	An Apple Watch long-look notification icon.
`60x60`	The main iPhone app icon for iOS 7 or later.
`76x76`	The main iPad app icon for iOS 7 or later.
`83.5x83.5`	The main iPad Pro app icon.
`86x86`	A 38mm Apple Watch short-look notification icon.
`98x98`	A 42mm Apple Watch short-look notification icon.
`128x128`	An OS X icon.
`256x256`	An OS X icon.
`512x512`	An OS X icon.
`1024x1024`	The App Store icon.

scale

See scale in Image Set Type.

subtype

The type of Apple Watch when there is more than one icon size for a role.

**Table 6-3**`subtype` values
Value	Description
Tag not included	The icon is not for Apple Watch.
`38mm`	The icon is for a 38mm Apple Watch.
`42mm`	The icon is for a 42mm Apple Watch.

role

The role for an Apple Watch icon (Table 6-4).

**Table 6-4**`role` values
Value	Description
Tag not included	The icon is not for Apple Watch.
`notificationCenter`	The icon is used in the notification center.
`companionSettings`	The icon is used in settings.
`appLauncher`	The icon is used in the app launcher.
`longLook`	The icon is used for a long-look notification.
`quickLook`	The icon is used for a short-look notification.

Sample Contents.json File

        {
   "images" : [
      {
         "filename" : "my-iphone-app",
         "idiom" : "iphone",
         "size" : "60x60",
         "scale" : "2x",
      },
      …
   ],
   "info" : {
      "author" : "com.developerName",
      "version" : 1
   }
}

      