How to configure multiple wifi networks on a Raspberrry Pi Zero W

If you install Raspian on a Raspberrry Pi Zero W one essential step is to setup Wifi. You save a configuration file called wpa_supplicant.conf on the boot-Partition. But how do you configure multiple networks in one step?

If you wish to configure multiple Wifi networks, just add another network section to your wpa_supplicant.conf file. Here’s an example:

country=DE 
ctrl_interface=DIR=/var/run/wpa_supplicant GROUP=netdev 
update_config=1 

network={
     ssid="SSID_1"
     scan_ssid=1
     psk="PASSWORD_1"
     key_mgmt=WPA-PSK
     id_str="ID_1"
}

network={
     ssid="SSID_2"
     scan_ssid=1
     psk="PASSWORD_2"
     key_mgmt=WPA-PSK
     id_str="ID_2"
}

Of course you will have to set SSID_1, SSID_2, PASSWORD_1 and PASSWORD_2 according to your Wifi router’s settings. Use the ÌD_1 and ID_2 properties, to give the networks a good description. For instance “work”, “office”, “home” or “school” might be sufficient.

Additionaly you can add a priority option to the network configuration. This option is helpful, when different Wifi networks are available simultaneously. In this case the network with the highest priority (lowest number) is selected.