I finally found a succinct guide to setting up a custom Namecheap subdomain with GitHub pages.
My objective was to redirect my GitHub user page
ellatronic.github.io to my custom subdomain
projects.ellatronic.com. This process was actually alot easier than the hours it took me to figure it out, mostly due to the new format of the Namecheap dashboard and the old format shown in other guides I referenced.
Log in to Namecheap, go to Dashboard > Domain List. Then click Manage on the domain you want. Click Advanced DNS, then under Host Records click Add New Record. Enter the following:
Host: the subdomain name, for me this is
Value: the GitHub pages URL, for me this is
ellatronic.github.io. Namecheap will automatically add the last “
.” if you forget it.
Press the green checkmark to save the record.
Next, go to the GitHub user page repo (
username.github.io), for me it is
ellatronic.github.io. Add a
CNAME file containing
subdomain.domain.com, so mine is
projects.ellatronic.com. Make sure
CNAME is in all capitals. Do not put
http:// before the subdomain.