NPOI VS EPPlus

NPOI (Open source, MIT)

For .NET Core you can use - https://github.com/nissl-lab/npoi - https://github.com/Jetro223/DocXNETCore

I use NPOI https://github.com/nissl-lab/npoi its a popular package for reading Excel. It is both faster than interop and free (open source).

Have you tried NPOI?

Competitor#2 (NPOI - v2.5.6)

If you are trying to *create* Excel files, then you might take a look at [NPOI](https://github.com/nissl-lab/npoi) which is also open source with a permissive license. There is also [ClosedXml](https://github.com/ClosedXML/ClosedXML), which has these capabilities.

I'd like to use NPOI to deal with Excel files. It's open source and you don't have to install Microsoft Office.

EPPlus ExcelDataReader NPOI

Like others, I recommend using the ImportExcel module. It uses and wraps EPPlus Software (EPPlus - Create advanced Excel spreadsheets using .NET (GitHub Project Old / New)) which is a DLL that is included with the ImportExcel PowerShell Module.

Their documentation looks okay. I doubt you're going to get many people familiar with a specific library here.

If you're copypasting stuff from excel, another approach I used in a different project is this package: https://github.com/EPPlusSoftware/EPPlus - which works in Blazor. You'd just let users drag/drop or upload their excel and import it, instead of copypasting

There is one Excel Library that I would recommend using in C# and that EPPlus. Its great and its free for non-commercial use. The API is simple to use and its got great documentation.

There is a Getting Started section in GitHub and complete API documentation on the home page

I've personally had a great experience working with EPPlus. It has both commercial and non-commercial/free licenses: https://epplussoftware.com/