To use a custom favicon for your Ghost blog:

Copy your favicon.ico file to the /assets folder inside your theme folder (/blog/content/themes/themeName/assets).

Open the default.hbs file of your theme

On line ~15 replace

<link rel="shortcut icon" href="{{asset "favicon.ico"}}">

with

<link rel="shortcut icon" href="{{asset "/favicon.ico"}}">

Save the default.hbs file, and refresh your blog.

That's really all there is to it. Ghost uses this default favicon, unless you specify your own.

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