1. ExcelDataReader Lightweight and fast library written in C# for reading Microsoft Excel files
Main Features Support Excel file format: OpenXml, BIFF8, BIFF5, BIFF4, BIFF3, BIFF2, CSV References https://github.com/ExcelDataReader/ExcelDataReader https://www.nuget.org/packages/ExcelDataReader 2. NPOI This project is the .NET version of POI Java project. With NPOI, you can read/write Office 2003/2007 files very easily.
Main Features It's totally free to use Cover most features of Excel (cell style, data format, formula and so on) Supported formats: xls, xlsx, docx.