Ideal size for .ico

What is an ideal size for a .ico file, that would sit in the top corner of a window?开发者_JAVA技巧

Short answer: 16 x 16 pixels.

Long answer:

.ico files can actually contain multiple images, at multiple colour depths - you can provide 16x16, 32x32, 48x48 and 64x64 in a single file and the OS will pick the best one to show.

Of course to keep the file size low you don't want to put too many in there, but if you think people might be saving a link on their desktop (say it's a web application) then it's probably a good move.

See Microsoft's recommendations.

Basically, 16x16, 32x32, 48x48, and 256x256 for application icons. I guess the window icon is a toolbar icon so 16x16, 24x24 and 32x32.

To originally figure this out when wanted to start making .ico images I opened a good looking icon already being used in Windows 11 with GIMP. I found nine layers 256 128 64 48 40 32 24 20 and 16. So this is kind of the formula I've been following creating the icons in Gimp and none of my icons fail ever they always display no matter what size they are. With GIMP you can take any single image and turn it into a multi-layer icon, you just have to know how to do a bit of image editing.But it %100 free.