Import excel or csv data for collection
Scott Jordan commented
StashMyComics has an import feature. They have a template Excel file you can download. It is incumbent on you to conform your data to match their schema. As for value matching, it does a best guess on the series/title. It them presents a 2 column table with the imported values on the left. The right column has a dropdown of possible series names. Once you select a series match it down an issue number search. You check the boxes of the issues to import.
It isn't perfect, but it gets you 90% of the way there saving many, many hours of manual entry.
As Zlours was saying it is virtually impossible. The reason for this is your spreadsheet might call it ASM 666 Orbital but we know it as Amazing Spider-Man 666re-40.
We have discussed trying to build a self learning import system from other trackers...the more it is used the more accurate it will be...but unfortunately the same problem exists...
import would be difficult because the fields and the exact titles & issues (imagine variant covers) would have to match exactly as it's entered in the database.