There are only 3 significant points which Xcode takes into account when it accepts drag and drop of the batch of the image files into any image asset (not only App Icon):
- the real image width and height what Xcode gets right from the file
- scale qualifier in the filename:
@2x, @3x
- idiom qualifier in the filename:
~ipad, ~car, ~mac, ~ios-marketing, ~watch-marketing
The additional qualifiers in the filename may be required to distinguish files with same scale and idiom suffixes but different size (e.g. 83.5@2x~ipad and 76@2x~ipad).
Example of possible drag and drop acceptable filenames with minimally required qualifiers is below.
iOS
// App Icons
app-icon@2x.png // iPhone | 60pt x 60pt | actual size: 120px x 120px
app-icon@3x.png // iPhone | 60pt x 60pt | actual size: 180px x 180px
app-icon~ipad.png // iPad | 76pt x 76pt | actual size: 76px x 76px
app-icon@2x~ipad.png // iPad | 76pt x 76pt | actual size: 152px x 152px
app-icon-83.5@2x~ipad.png // iPad Pro | 83.5pt x 83.5pt | actual size: 167px x 167px
// Notification Icons
app-icon-20~ipad.png // iPad | 20pt x 20pt | actual size: 20px x 20px
app-icon-20@2x~ipad.png // iPad | 20pt x 20pt | actual size: 40px x 40px
app-icon-20@2x.png // iPhone | 20pt x 20pt | actual size: 40px x 40px
app-icon-20@3x.png // iPhone | 20pt x 20pt | actual size: 60px x 60px
// Settings Icons
app-icon-29.png // iPhone | 29pt x 29pt | actual size: 29px x 29px
app-icon-29~ipad.png // iPad | 29pt x 29pt | actual size: 29px x 29px
app-icon-29@2x~ipad.png // iPad | 29pt x 29pt | actual size: 58px x 58px
app-icon-29@2x.png // iPhone | 29pt x 29pt | actual size: 58px x 58px
app-icon-29@3x.png // iPhone | 29pt x 29pt | actual size: 87px x 87px
// Spotlight Icons
app-icon-40~ipad.png // iPad | 40pt x 40pt | actual size: 40px x 40px
app-icon-40@2x~ipad.png // iPad | 40pt x 40pt | actual size: 80px x 80px
app-icon-40@2x.png // iPhone | 40pt x 40pt | actual size: 80px x 80px
app-icon-40@3x.png // iPhone | 40pt x 40pt | actual size: 120px x 120px
// App Store
app-icon~ios-marketing.png // 1024pt x 1024pt | actual size: 1024px x 1024px
Mac
app-icon~mac.png // actual size: 16px x 16px
app-icon-16@2x~mac.png // actual size: 32px x 32px
app-icon-32~mac.png // actual size: 32px x 32px
app-icon-32@2x~mac.png // actual size: 64px x 64px
app-icon-128~mac.png // actual size: 128px x 128px
app-icon-128@2x~mac.png // actual size: 256px x 256px
app-icon-256~mac.png // actual size: 256px x 256px
app-icon-256@2x~mac.png // actual size: 512px x 512px
app-icon-512~mac.png // actual size: 512px x 512px
app-icon-512@2x~mac.png // actual size: 1024px x 1024px | also used for Mac App Store
CarPlay
app-icon@2x~car.png // 60pt x 60pt | actual size: 120px x 120px
app-icon@3x~car.png // 60pt x 60pt | actual size: 180px x 180px
Apple Watch
The correct format for qualifying roles (e.g. Companion Settings or Quick Look) and subtypes (38 mm, 42 mm) was not found. So the only acceptable file here is the one for App Store.
app_icon~watch-marketing.png // 1024pt x 1024pt | actual size: 1024px x 1024px
