IP basics · 3 minute read

Public vs. private IP: which one do you need?

Your laptop might show an address starting with 192.168., while this website shows something completely different. Both can be correct. They describe different parts of your connection.

The difference at a glance

Public and private IP addresses compared
Address	Where it's used	Useful for
Public IP	Across the internet	Checking what a website sees, VPN comparisons, network support
Private IP	Inside your local network	Connecting to a printer, router, or another local device

Why a whole household can share one public IP

On a typical home IPv4 network, your router gives each device a private address. When you open a website, the router translates the connection to a public address using network address translation (NAT). The website sees that public address, while your router keeps track of which device should receive the response.

Your provider may also use carrier-grade NAT, sharing a public IPv4 address between customers. That is one reason your router's internet-facing address can differ from an online IP check. With IPv6, devices can have their own globally routable addresses, so the shared-address model does not apply to every connection.

Recognise a private IPv4 address

The private ranges are 10.0.0.0–10.255.255.255, 172.16.0.0–172.31.255.255, and 192.168.0.0–192.168.255.255. These addresses are reused in many separate networks and cannot identify a unique internet connection.

127.0.0.1 is different again: it means your own device, also called localhost. An address beginning with 169.254. is link-local; on an IPv4 network, it can appear when automatic address assignment fails.

Find your local address

On Windows

Open Settings → Network & internet, then open the properties of your connected network. Look for IPv4 address. You can also open Command Prompt and run ipconfig; use the active Wi-Fi or Ethernet adapter, not a disconnected one. See Microsoft's network settings guide.

On Mac

Open System Settings → Network, choose your active connection, then Details → TCP/IP. The IP address belongs to your Mac on that network; the Router field identifies the gateway. See Apple's TCP/IP settings guide.

Which address should you send to support?

For trouble reaching a website or a request to allow your connection through a firewall, support will usually need your public IP. For a printer or device on your home network, they will usually need its local IP. Ask which one they need, and share it through a trusted support channel.

Our homepage shows the public address used to reach this site. “Copy diagnostic summary” includes that address and the approximate location fields, so you can provide the visible details together.