Most "app icon size" charts online still list fifteen iOS sizes and a dozen favicons. You don't need most of them anymore. Here's what each platform actually asks for today, and the two mistakes that get icons cropped or rejected.

Start with one 1024×1024 PNG

Everything below can come from a single square image:

1024×1024 pixels , exactly square

PNG , so there are no compression artifacts

No transparency and no rounded corners. Fill the whole square. Both Apple and Google apply their own corner mask, so if you round the corners yourself, you get a rounded square inside a rounded square.

No drop shadow around the edge. Google Play adds its own. Shadows and lighting inside the artwork are fine.

iOS: one file

Since Xcode 14, an app icon set can contain a single 1024×1024 image. Xcode generates every runtime size (Home Screen, Spotlight, Settings, notifications, iPhone and iPad) at build time.

So for iOS you need:

File Size Notes

App icon 1024×1024 No alpha channel.…