FAQ

How can I get HTTPS/TLS support for my subdomain?

HTTPS/TLS support is the default. So you don't have to do anything. Only if you don't want to use Cloudflares "Universal SSL" Service you have to add a '//noCF' comment in the line of your requested subdomain. See here.

Why did my subdomain.github.io disappear?

This is what happens when you add a CNAME file to a user/organisation GitHub page. It redirects to subdomain.js.org which doesn't exist yet. This is only temporary behaviour until the js.org subdomain is activated.