I checked your travel Wien-Munich on www.obb.at/en (Austrian railways) and it seems like there’s an uncertainty in the timetable because of planned engineering works, so not every train is showing or is bookable already. I’lld suggest to check again in a couple of days/weeks.

Other interesting websites to buy train tickets for you will be www.bahn.com (German railways) or www.sbb.ch/en (Swiss railways).

Discounts are usually automatically given by age. Discount cards or mostly only interesting if from a certain number of trips. I doubt there will be one that’s interesting for you, buyt you never know. Someone else may know more about this.

You’re choosing busy travel days (15th of August is a public holiday in a lot of countries/regions) and coincides with the end of a lot of people’s holidays, so trains will be quite full and expensive looking at prices.

Switzerland is expensive, so a Eurail pass will be easily good value for money. Best compare prices with ordinary tickets on the websites mentioned above and the prices of Interrail/Eurail passes.

So are you considering to buy a Eurail pass or not? A eurail pass enables you to take 95% of all trains in Europe, and gives you great flexibility.

Do you plan to do more trips than those two you mentioned?

thanks for the detailed answer.

What's strange is that I see this trip being sold on sites like omio.com.

The Euril card is only intended for Europeans, so unfortunately I can't buy the card.

Eurail is for persons NOT living in Europe, Interrail is for persons living IN Europe.

 @Anat Tairy It’s always best to buy the tickets directly with the transport company, not third party website like omio. They don’t have the latest information.

Some general info on Eurail passes is found here: https://www.seat61.com/how-to-use-a-eurail-pass.htm

Ok

my trip plan is: 

12.8 landing in Vienna

14.8 Vienna to Munich 

15.8 Munich to Zurich 

then travel Swiss for 3 days.

I thought to buy the Swiss pass

now i see it is better to buy the eurail pass.

does it cover all the train in Swiss?

do I need to bay reservations seats?

Seat reservations are not a thing within Switzerland. They are required on Vienna - Munich - Zurich (3€ per person).

The Eurail Pass covers all regular trains of the country (same as the Swiss Travel Pass). Both passes are not valid on touristy railways such as Jungfraujoch, Gornergrat, Pilatus,…

Most of the time you get a 25-50% discount on these.