IconZilla

IconZilla enables you to generate your ICNS files with just two click. Drag and drop a 1024x1024 or larger image files into IconZilla and it is ready. The generated ICNS file will contains all currently desired icon sizes: - icon_16x16 - icon_16x16@2x - icon_32x32 - icon_32x32@2x - icon_128x128 - icon_128x128@2x - icon_256x256 - icon_256x256@2x - icon_512x512 - icon_512x512@2x IconZilla also supports upscaling of smaller images for your icon but best results are achieved with images the size of 1024x1024 or larger with an 1:1 aspect ratio.