Sending blank messages is not a useful thing; but you can use it for fun and surprise to your friends, there is no option in WhatsApp for sending blank messages; but using a app you can do this, let see how to surprise your friend but don’t miss use this.
1. Go to google play store download and install “Empty Text – Send Bank text” app
2. Open the app tap on “Send empty text” it will redirect to WhatsApp select contact and simply tap on “Send” icon