ESP8266 on WiFi without password, possible?

Question

Is it possible to connect to an SSID that does not require a password? My project using ESP8266-01 modules will sometimes be used in non-password protected guest networks.

Answer 1

Yes, it works! You can use:

WiFi.begin(ssid, NULL)

or even leave the passphrase empty, because it is optional:

WiFi.begin(ssid)

Reference: https://www.arduino.cc/en/Reference/WiFiBegin