do wifi addresses change

The Wi-Fi Address of your phone.......Settings > General > About > Wi-Fi Address......does not change. Some people call this the MAC Address of the phone. It is a unique identifying number.

The IP Address that is assigned by a Wi-Fi router on a network to the iPhone can change. Often, it is something like 192.168.1.x. for example.

But.....just to make things more confusing, the iPhone can display what is known as a Private Wi-Fi Address......Settings > Wi-Fi > Tap on the blue "i" next to the network name.......so the Wi-Fi router does not "see" the actual real Wi-Fi Address or MAC Address of the iPhone in the list of devices that are currently connected to the router's Wi-Fi network.

biscottibaker wrote:

do wifi addresses change

To further complicate matters, if you turn on Private Wi-Fi Address after going to Settings/Wi-Fi and tapping on the i next to your network name then your Wi-Fi (MAC) address will change to hide your identity.

Thus, it would be helpful if you could provide additional information about what you are asking.

If you mean the IP address issued by the DHCP server on a WiFi network, yes. It can change.

The IP address that the router uses to connect to the internet will also change periodically.