Update: I no longer maintain this blog using Octopress, but I will leave this post here in case it may be of use to people.

I found several suggestions for how to change the default Octopress favicon (a black and grey “O”), such as adding your favicon.ico to source/, and then editing source/_includes/custom/head.html with the line

{% assign favicon = '/favicon.ico' %}

For some reason that didn’t work for me. Maybe it’s because my favicon.ico file was unreadable/corrupt. I used favicon-generator to create my favicon, which I downloaded as favicon.ico, but I couldn’t open it in feh either.

The solution was to convert to png using ImageMagick’s convert command:

$ convert favicon.ico favicon.png

After that, I was able both to view the favicon in feh and to replace the default Octopress favicon, without even touching source/_includes/custom/head.html. The reason is that the default favicon was named favicon.png, which I simply overwrite. Very easy, and plus there’s no need to keep around the default favicon anyway.

P.S. When testing if Octopress finds your favicon, refreshing your browser may not be enough. You may have to restart the browser first to clear the old favicon.