In Vienna, SIM cards can be bought in Hofer stores or in kiosks selling small electronics. Popular operators are Drei , Hot , Magenta and Educom. I bought a SIM card from the latter. Especially since the operator’s office is located near the campus of the University of Vienna.
I chose a tariff with 45 GB of Internet, 110 SMS and 2199 minutes. It costs 10 € per month. The Internet is more than enough, and I do not use SMS and minutes for calls. Therefore, I have never bought additional packages. I am generally happy with the connection. The Internet works almost everywhere, but for some reason it does not work in some stores.
Educom also has a convenient app where you can change your tariff, buy extra gigabytes and pay for the next month. I connected payment from a card, and the balance is replenished automatically.
Internet and Wi-Fi. There is free Wi-Fi in my dorm. The speed is great – sites and videos load quickly. I have never connected to the Internet in public places, but I think that cafes and restaurants have it. I have not heard of free Wi-Fi in public transport.
