34

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

CharlesB
  • 86,532
  • 28
  • 194
  • 218

3 Answers3

46

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.

Greg
  • 316,276
  • 54
  • 369
  • 333
  • 12
    16 x 16 might be stretched too much in high DPI. A 32-bit icon with 64x64, 32x32, and 16x16 sizes is only ~22k, so you should try to keep all different sizes and let the OS choose. – Michael Oct 06 '09 at 16:50
  • Upvoted! I didn't know that .ico files can actually contain multiple icons of varying sizes and that browsers would choose the best one. Thanks! – Raj Jul 02 '13 at 18:51
  • 2
    You can use the [ConvertICO](http://convertico.org/Multi_Image_to_one_icon/) to bundle many png files into one ico file. – Mizipzor Jul 31 '13 at 12:04
  • 1
    Is it possible to do this in Photoshop? – user1448031 Apr 01 '14 at 02:59
  • 1
    Gimp can do this – Martin Fehrs Oct 01 '20 at 14:59
5

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.

Timmmm
  • 88,195
  • 71
  • 364
  • 509
0

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.

Zantetsuken
  • 1
  • 2