127.0.0.0/8

127.0.0.0/8 is loopback

Last updated 2 Nov 2026 from the IANA IPv4 Special-Purpose Address Registry

Short answer

127.0.0.0/8 is loopback: any address in it, usually 127.0.0.1, means “this same device”.

Block	127.0.0.0/8
First – last	127.0.0.0 – 127.255.255.255
Size	16,777,216 addresses
Name in the registry	Loopback
Defined in	RFC 1122, Section 3.2.1.3
Allocated	1981-09
Valid as source / destination	False / False
Forwardable	False
Globally reachable	False

What it means

RFC 1122 reserves 127.0.0.0/8 for loopback. Traffic sent to 127.0.0.1 never leaves the computer; it goes straight back to programs running on it. Developers use it to test servers locally, and “localhost” resolves to it.

An address in this range cannot belong to anyone else and cannot be used to reach you over the internet.

Want the address websites actually see for you? Open the Truth Check.

Sources

IANA IPv4 Special-Purpose Address Registry (CC0) · checked 2 Nov 2026
RFC 1122