localhost subdomains done right

Various similar services have existed then stopped working after a single-digit number of years when the owner of the domain stopped paying or maintaining.

Currently working equivalents

lvh.me

anything.lvh.me

fbi.com

anything.fbi.com

anything-that-isnt-a-numeric-ip.traefik.me

127.0.0.1.nip.io 127.0.0.1.sslip.io 127-0-0-1.backname.io

Since the point is to have multiple names available you can also use 127.0.0.2.nip.io etc (if your webserver is listening on 0.0.0.0)

There are a few services that will point a subdomain name at an ip of your choice

localhost.ipq.co localhost.fdns.uk

Someone has already created localhost1.ipq.co localhost2.ipq.co etc