What is my hostname?

Your Hostname

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More about your connection

What is a hostname?

The displayed hostname is the reverse DNS name of your public IP address. Where DNS translates a domain name such as example.com into an IP address, reverse DNS does the opposite: it looks up which name belongs to an IP address. If your address has no reverse DNS record, the tool shows the IP address itself.

How reverse DNS works

Reverse DNS uses a special record type called a PTR record. To find the hostname for 203.0.113.42, a resolver reverses the numbers and queries 42.113.0.203.in-addr.arpa. The answer is whatever name the owner of that IP range has published, for example 203-0-113-42.dsl.example-isp.net.

Because the record lives in the IP owner’s DNS zone, you can’t set it from your own domain. For a home connection, your ISP controls it.

What your hostname can reveal

ISPs often generate hostnames automatically, and they tend to follow a pattern:

  • Your IP address, written into the name with dashes
  • The ISP’s domain, which identifies your provider
  • The connection type, such as dsl, cable, fiber or mobile
  • A city or region code, which can hint at your location

A hostname that contains a hosting company or VPN provider’s domain is a strong sign that traffic is coming through a server rather than a home connection.

Why hostnames matter

  • Email delivery: mail servers check that a sending IP has a PTR record whose name points back to the same IP (forward-confirmed reverse DNS).
  • Logs and security: administrators read hostnames in server logs because they are easier to recognize than raw IP addresses.
  • Troubleshooting: tools such as traceroute show hostnames for each hop, making it easier to see where a connection slows down.

Looking up a hostname yourself

On any computer you can run a reverse lookup from the command line:

  • Windows, macOS or Linux: nslookup 203.0.113.42
  • macOS or Linux: dig -x 203.0.113.42

Frequently asked questions

Why does the tool show my IP address instead of a hostname?

Your IP address has no reverse DNS record, so there is no hostname to show. This is common and does not affect normal browsing. Only the owner of the IP range, usually your ISP, can create one.

Is my hostname the same as my computer name?

No. Your computer name is set on your device and only visible on your local network. The hostname shown here belongs to your public IP address and is set by whoever controls that address.

Can I change my hostname?

Only the owner of the IP address can change its reverse DNS record. On a home connection that is your ISP. Business and server customers can usually request a custom hostname.

Why do mail servers check the hostname?

Many mail servers reject or flag email from IP addresses without a matching reverse DNS record, because spam is often sent from such addresses. Anyone running a mail server needs a hostname that matches its forward DNS record.