That would be some feat of programming if it were available, I imagine your coins are not all listed the same way that they are on numista and so matching them would be pretty difficult. Happy to be proved wrong, but probably best if you start cataloguing now.
It could be done using a program called "Dataload" but you would need to be very conversant with how it extracts data from a spreadsheet and places it on a form webpage in Numista.
Also because different people would have their collection sorted and stored differently on any given spreadsheet a Dataload Script would not work for someone else with a different way of displaying their collection on a spreadsheet.
If you are not computer savvy it would be better, and probably faster, to just start entering your collection manually.
I used to use "Dataload" when I worked as a Business Analyst and whenever it was used lots of testing had to be done in a Test Environment before we ever used it in any Production Environment. Because there is no way to test a Dataload Script on Numista, it would not be a good idea to try it.
Cheers Mike
Master Referee - See my profile for what I collect.
Status changed to Rejected(Xavier, 14 Feb 2021, 14:52)