train Krakow to Budapest

Yes, but it may only be couchettes. Operated by OEBB, but not a Nightjet.

I looked on the Polrail site, there are singles, doubles and triples available. Put your age in and hit search https://booking.polrail.com/index.php?main_page=page_5&from=Krakow&to=Budapest&date=20-02-2024&language=en

Yes, and it does have sleepers. But it's not operated by ÖBB as far as I know.
https://www.seat61.com/international-trains/trains-from-Krakow.htm#Krakow_to_Budapest

Does it matter who operates it? Get the ticket at the Polish site. Where you shoud go anyway.

The schedule is 22:43 to 08:29 which means you get to sleep about 11:30 pm and you wake up about 7:30 am.

You arrive at Nyugati station in Budapest. Recent exterior renovations really came out well. This is a Eiffel & Co. design as are a number of the buildings in the neighborhood. From here you can take the metro to whereever you are staying or to a place to store your luggage.

Oh, storing your luggage! At the hotel until check-in time or if you are using an Airbnb, check out "The Lion's Locker" for bag storage and for breakfast (no food on the train).

Then head to the Széchenyi Bath House (book a ticket in advance and get a cabana). The advantage is you get to take a shower as part of the experience and after a night in a train I would think the shower would be nice (especially if you are traveling in warm weather).

Now its noon - thirty. Maybe get into that Airbnb now, but the hotel is still 90 minutes for checkin.....

And sure, LOT has a flight that arrives in Budapest about noon after about 3.5 hour one stop flight. But that will cost you $140 a ticket while the train will be close to $125 a ticket (dbl) and with the train you will save another $75 to $150 in accommodation cost.

The small inconvenience of traveling back and forth to your Krakow hotel to retreive your bags prior to the train departure and the small inconvinience of storing your bags at the other end and showers, etc, not to mention the "romance of the rail" (all blessed night long .. click. click. rattle, rattle ) .............. Train for me every time!.

No, actually for the extra cost of maybe $150 I would fly. But no wrong answer here. And everyone should ride a night train at least once in their life.

I like the various night trains operated by OeBB, have taken almost only the Night Jet for all the night train rides. The IC operated by DB is OK but given a choice between DB's IC and OeBB Night Jet, I'll choose the NJ since IC leaves the lights on all night long.

Not really a big deal, only a minor preference, if the prices are comparable.