You need to know the name of the file before you can download it.
Indeed. And /favicon.ico might not be a Windows ICO file, but instead be a PNG, GIF, or some other image format. I thought that’s what you were (correctly) pointing out when you wrote “it doesn’t have to be an *.ico file”. In such cases, the HTTP Content-Type field tells what image format it is.
If I were to blindly download /favicon.ico, I’d naturally get a 404 page:
Ah, so it turns out you were thinking of cases where /favicon.ico doesn’t exist at all. That can also happen, but your suggestion to “try different file extensions” is not the answer, as you can see if you try to curl /favicon.png, /favicon.gif, etc. The correct approach is to parse a web page’s HTML in search of a favicon URL, which you did in your above reply, but that’s not the same thing as what you originally suggested.
Indeed. And /favicon.ico might not be a Windows ICO file, but instead be a PNG, GIF, or some other image format. I thought that’s what you were (correctly) pointing out when you wrote “it doesn’t have to be an *.ico file”. In such cases, the HTTP Content-Type field tells what image format it is.
Ah, so it turns out you were thinking of cases where /favicon.ico doesn’t exist at all. That can also happen, but your suggestion to “try different file extensions” is not the answer, as you can see if you try to curl /favicon.png, /favicon.gif, etc. The correct approach is to parse a web page’s HTML in search of a favicon URL, which you did in your above reply, but that’s not the same thing as what you originally suggested.