PNG to ICO converter

1. 1

   Add the image

   A square logo with a transparent background works best.

2. 2

   Pick the sizes

   16, 32 and 48 for a favicon; add 256 for Windows. Check each one in the preview.

3. 3

   Download the ICO

   One .ico file holds every size you picked.

An ICO holds the same picture at several sizes, and whatever shows it picks the one closest to the size it needs: a browser tab takes 16 or 32 pixels, the Windows desktop larger ones.

Microsoft's icon guidelines give the full set for a Windows app as 16, 32, 48 and 256 pixels, with only the 256 copy compressed as PNG. This tool follows that: 256 goes in as PNG, the smaller sizes as 32-bit bitmaps with their transparency.

At 16 pixels, fine lines and small text vanish. Check the preview: if the logo turns to mush, a simpler mark, such as one letter or the symbol alone, reads better as a favicon.

A picture that isn't square is centered, with clear space on the short sides.

The same file from the command line:

• magick logo.png -define icon:auto-resize=256,48,32,16 favicon.ico

No. The sizes are drawn and the ICO is written in your browser.

16, 32 and 48 pixels cover browser tabs, bookmarks and Windows shortcuts to a site.

Yes. Every size keeps the image's transparency.

Yes. Any image your browser opens works. A JPG has no transparency, so its background stays; an SVG is drawn large first so even the 256 size is sharp.

In the root of your site, so it's at yoursite.com/favicon.ico. Browsers look for it there.