Find your private IP address on Windows, Mac, iPhone and Android
If the address you are looking for starts with 192.168, it is not the one this site shows. That is your private address, and it is read on the device itself.
Public or private: which one do you need?
Your device has both. The public address belongs to your connection and is assigned by your provider: it is what websites see, and it is what the home page shows. Every device in your home shares it.
The private address identifies one device inside your home network. Your router assigns it, it never travels across the Internet, and it differs for every device. It is the one you need to set up a printer, reach a NAS, open a port forward or diagnose a local network problem.
You recognise it by how it starts: 192.168, 10., or 172.16 through 172.31. Those ranges are reserved for internal use and routed nowhere.
Windows
Through the interface: Settings → Network & Internet → click your Wi-Fi or Ethernet connection, then scroll to IPv4 address.
From the command line, faster: open Command Prompt and type
ipconfig. Find the active adapter and its IPv4
Address line. The Default Gateway just below gives
you your router's address, handy for reaching its interface.
macOS
System Settings → Network → select your connection → Details → TCP/IP tab.
In Terminal: ipconfig getifaddr en0 for Wi-Fi, or en1
depending on the model. ifconfig shows everything but needs
sorting through.
iPhone and iPad
Settings → Wi-Fi → tap the information button, the small circled "i", to the right of the network you are on. The address appears under IP Address.
On 4G or 5G this is not exposed: iOS only shows the local address on a Wi-Fi connection.
Android
The path varies by manufacturer, but the logic is constant: Settings → Network & internet → Wi-Fi → tap the connected network → Advanced.
A more reliable route, independent of the manufacturer's skin: Settings → About phone → Status, which lists the IP address and the MAC address.
Linux
ip addr show lists every interface. The address you want follows
inet on the active one. Straight to the point:
hostname -I.
If the address starts with 169.254
That is not a normal address. Your device failed to obtain one from your router and assigned itself one instead. It signals a problem: unplugged cable, DHCP service stopped on the router, or Wi-Fi connected but with no configuration received.
The usual reflex is to restart the router, then the device. If the address persists, the problem is on the router side.
Why this site cannot give it to you
A web page only sees the public address the request arrived from. Your private address stays inside your network, and that is exactly its job. The one mechanism that occasionally leaked it, WebRTC, is now neutralised by browsers, which announce a random name instead - you can see this for yourself in the "What your browser reveals as well" section of the home page.