Which should I use:
<link rel="SHORTCUT ICON" type="image/x-icon" href="favicon.ico" />
<link rel="icon" type="image/ico" href="favicon.ico" />
OK, figured this out for myself...
<link rel="icon" will work in IE8, 9, FX and Chrome but not in IE6 or 7. The
rel="shortcut icon" is supported by IE6 & 7.
The W3C standards state a space delimited list and that the key is just
icon. This means
shortcut icon works in all browsers - handled incorrectly by IE and as a compound key in everything else.
All browsers appear to accept and handle the Windows icon format for the file.
IE expects this to be served as MIME type
image/vnd.microsoft.icon but only seems to consistently work if the content type is
Everything else expects
image/ico but pretty much ignores it.
So the best format is:
<link rel="shortcut icon" href="favicon.ico" />
However if IE has problems handling the file or your server is not passing the
image/x-icon content type in the headers it can help to specify the IE expected type:
<link rel="shortcut icon" type="image/x-icon" href="favicon.ico" />