There are a couple of relevant catalogs/books but not all of them are available in pdf. At least I'm not aware of it.
Corpus Nummorum Hungariae (CNH)
https://en.numista.com/L104342 and https://en.numista.com/L104343
Pro: covers the whole middle ages, has decent drawings, is available on Scribd as a pdf.
Con: Very outdated, a lot of the attributions are incorrect.
Münzkatalog Ungarn
https://en.numista.com/L100006
Pro: It covers the whole Hungarian coinage up until the 1970s, not just the middle ages, it's reasonably up-to-date, it's available on Scribd.
Con: Hard to find the book itself and when it's available, it's very expensive.
Magyar Éremhatározó 1-3 (ÉH)
https://en.numista.com/L110772
Pro: It covers the whole Hungarian coinage up until the First World War, not just the middle ages, it's mostly up-to-date, available on Scribd
Con: very simplistic drawings, omits a lot of variations and details, mostly a cheap, easily available gateway book for new collectors but there are more serious and detailed books than this.
Az Árpád-kori magyar pénzek I-III + Az Anjou-kori magyar pénzek
https://en.numista.com/L110922 and https://en.numista.com/L105529
Pro: Very, very detailed. It contains all known variations of a given coin. This is the most up-to-date and most detailed catalog for medieval Hungarian coins at the moment.
Con: I don't think it's available in pdf, but the books are not expensive (~15€) and not hard to find. Also it only covers the coinage of 1000-1389 and I don't know if there are plans to continue the series for the late middle ages.
Numista itself 🙂
Pro: Pretty much all medieval Hungarian coins are already in Numista
Con: A lot of them doesn't have images, so it's not perfect for identification
I suggest to start with the ÉH and with Numista and if you're more interested, buy these books https://en.numista.com/L110922, https://en.numista.com/L105529.