.localhost
| IANA -- Internet Assigned Numbers Authority | |
| Introduced | 1999 |
|---|---|
| TLD type | Reserved top-level domain |
| Status | Reserved to prevent actual use |
| Registry | IANA |
| Sponsor | None |
| Intended use | Identifies the current local computer; reserved at the top level of the DNS to prevent remote addresses that conflict with this |
| Actual use | Much software, including Web browsers, lets you access local host this way |
| Registration restrictions | No registrations are possible, as this domain is not in the root |
| Structure | Has no structure; it's used directly as a hostname |
| Documents | RFC 2606 |
| Dispute policies | None |
| Registry website | None |
.localhost is a reserved top-level domain not intended for real use in the global DNS. It was defined in June 1999 by RFC 2606, along with .example, .invalid, and .test. Its reservation is intended to avoid confusion with the common localhost. Also, the ".localhost" TLD has traditionally been statically defined in host DNS implementations as having an A record pointing to the loop back IP address and is reserved for such use. Any other use would conflict with widely deployed code which assumes this use.