What is a hostname?
A hostname is a name associated with an IP address, easier to remember and work with than a
string of numbers. dns.google is, for example, the hostname associated with the
address 8.8.8.8.
The role of the DNS server
DNS (Domain Name System) is the Internet's phone book: it maps domain names (like
getmypublicip.com) to IP addresses. Every time you type an address into your
browser, a DNS request translates that name into an IP address before the connection can be
established.
getmypublicip.com
Domain name
DNS server
Translation
5.196.181.117
IP address
Reverse DNS
Reverse DNS does the opposite: starting from an IP address, it finds the associated hostname, when one exists. This is the method Get My Public IP uses to display the hostname during a lookup.
Hostname and connection stability
Some service providers name their dynamic IP blocks in a recognisable way (with words like dyn, dhcp, pool or cust in the hostname). Get My Public IP relies on these clues to estimate, without certainty, whether an address is probably static or dynamic — shown as a "Stability" badge on the result pages. This is an estimate, never a guarantee: only your service provider truly knows how your IP is assigned. See also the guide on static and dynamic IP addresses.
Ready to give it a try?
See an IP's hostname