'Naked' domains

By default, Google Sites have to be mapped to a subdomain and cannot be mapped to a naked domain.

A 'naked' domain is an internet domain name without the "www" or any other subdomains. For example, computerlanguage.com is a naked domain but www.computerlanguage.com is not, because it includes the www subdomain.

If you want your naked domain to point to your Google Site then you have to redirect the naked domain to your custom url