transportation from VIE to Wien HBf

First off, are you sure you want to go to Wien Hbf?

I ask because there are two other major stations, Wien Mitte and Wien Westbahnhof.

There is a special train to/from Wien Mitte and the airport, runs direct City Airport Train

For such a short journey, the price difference will be minimal for whenever you buy the
ticket, and if your inbound flight is delayed and you miss your original train, it may cost
you more if you have to buy a new ticket. I would say just buy it when you arrive.

⅞I've done this journey many times. No need to buy a ticket ahead of time. There are ticket machines near the OBB counter in the terminals and near the tracks themselves. They take both cash and cards. No need to reserve,

OBB Railjet operates the service. It's twice an hour and takes about 15 minutes.

For more information:

https://www.wien.info/en/travel-info/arrival-departure/airport-to-center/intercityexpress-349074

There is also an Airport Bus that operates between VIE and the HBF.

However, if you are going into Vienna itself, the HBF may not be your best destination station.

There is a special train to/from Wien Mitte and the airport, runs direct City Airport Train.

Locals view that train with outright contempt - and have done so on this forum. The S7 runs on the same tracks, takes just 15 minutes longer, and costs less than 6 Euro, as opposed to 14 Euro for the express.

To ride local transit in Vienna, get the WienMobil app - you can load multi-day passes onto it, and then transit becomes hop on/hop off - no turnstiles or fare validators to worry about.

Like in most of. the DACH area public transport is integrated in Vienna. So you do not buy a ticket for train, or tram, you buy a ticket from "Airport" to "Central Vienna" and it covers your trip all the way to your accommodation, using any mode of transportation. Train from airport to city, using RJ, IC, S or RE (anything but the CAT) and then onwards by metro, tram or bus.

Its all pretty straightforward really. You can use the OBB app to plan your trip. Just enter the street address of your hotel. It will show you the entire route, and allow you to buy a ticket,

If you do specifically want to get to Wien Hbf (eg to connect to another train) I would definitely recommend taking the Railjet rather than the S-Bahn. Depending on where exactly you want to go elsewhere in Austria, there might even be direct Railjets from the Airport without needing to change.