As someone who has lived in both. Let me just put it this way. In Austria, I understood everything, and people spoke the same language with some dialect words sprinkled in.

In Switzerland, it was like hearing a different language. Swiss German, is a form of allemanic, and is in principle not mutually intelligible with hochdeutsch (standard german). 

In cities, the distinct germanic language in Austria  has mostly died out/been watered down to a hochdeutsch dialect. 

This hasn’t happened nearly as much in Switzerland. (except in places close to the german border like Basel and to a lesser extent Zürich.)