Re: why hangouts doesn't have WiFi sms
Really so tell me why an imessage can send via WiFi and a hangout cannot.. Pretty simple to see
It can, and does... sending messages over Wi-Fi or Mobile Data connection is what Hangouts does. I do it all the time. I gave my old smartphone to my daughter (sans SIM). She sends me Hangouts messages (ONLY over Wi-Fi) all the time. If you can not send a message, it means the recipient does not have a Google account and can't receive native Hangouts messages.
Why does it work in iMessage, then? Because you are probably sending that iMessage to another iPhone user.... Try sending an iMessage message to someone with an Android phone. You can't.. it's impossible because Apple doesn't make Android apps. Thank God for that... the last thing we'd need is Apple kidnapping phone numbers of people with Android phones as well.
Now, someone with an iPhone can go to the App Store and download Hangouts, log on in and you'll be right as rain sending them Hangouts messages over a data connection.
But in both iMessage and Hangouts... they need to be registered with the service in order to take the native message types. Otherwise it's SMS-only over the phone connection.