Correct MIME Type for favicon ico

Question

According to the Internet Assigned Numbers Authority  IANA   all  ico file falls under the MIME type image vnd microsoft icon   Source   E g   lt link rel  icon  type  image vnd microsoft icon  href  favicon ico    gt   However  savvy internet guru  Paul Irish  claims this is wrong  and that it would actually be image x-icon   Source   E g   lt link rel  icon  type  image x-icon  href  favicon ico    gt   I know you can get away with not including a  type  for  ico files  but if you were going to include one  which should it be  Are there actually any problems with serving it as official IANA type

User · Answer

I think the root for this confusion is well explained in this wikipedia article.

While the IANA-registered MIME type for ICO files is image/vnd.microsoft.icon, it was submitted to IANA in 2003 by a third party and is not recognised by Microsoft software, which uses image/x-icon instead.

If even the inventor of the ICO format does not use the official MIME type, I will use image/x-icon, too.

User · Answer

When you re serving an  ico file to be used as a favicon  it doesn t matter  All major browsers recognize both mime types correctly  So you could put    lt  -- IE -- gt   lt link rel  shortcut icon  type  image x-icon  href  favicon ico    gt   lt  -- other browsers -- gt   lt link rel  icon  type  image x-icon  href  favicon ico    gt    or the same with image vnd microsoft icon  and it will work with all browsers    Note  There is no IANA specification for the MIME-type image x-icon  so it does appear that it is a little more unofficial than image vnd microsoft icon   The only case in which there is a difference is if you were trying to use an  ico file in an  lt img gt  tag  which is pretty unusual   Based on previous testing  some browsers would only display  ico files as images when they were served with the MIME-type image x-icon  More recent tests show  Chromium  Firefox and Edge are fine with both content types  IE11 is not  If you can  just avoid using ico files as images  use png

User · Answer

I have noticed that when using type  image vnd microsoft icon   the favicon fails to appear when the browser is not connected to the internet  But type  image x-icon  works whether the browser can connect to the internet  or not  When developing  at times I am not connected to the internet

[html] Correct MIME Type for favicon.ico?

Examples related to html

Examples related to browser

Examples related to mime-types

Examples related to favicon