Hop Off-Hop On
The hop off hop on bus is definitely an awesome way to see any city and a cheap waste of time :) Most of them allow you to pay on the bus when you show up or you can buy them online, be sure to download the app in advance and note when the bus stops. Also there are multiple lines so just be very careful. The hop-off hop-on in Budapest is just OK in all honesty. Its good to take you around town for example to Hero’s Square, to Buda to Pest etc. But in personal opinion it wasn’t that great primarily because a lot of the beauty and appeal of Budapest isn’t necessarily “bus” drive by sites.