EPPlus VS Sylvan.Data.Excel

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.

There is some additional samples at their old (abandoned) branch: https://github.com/JanKallman/EPPlus/tree/master/SampleApp

Love this version: https://www.nuget.org/packages/EPPlus/4.5.3.3

EPPlus ExcelDataReader NPOI

For reading JSON -> e.g. ServiceStack.Text. For writing into Excel -> Use EPPlus library version 4.5.3.3. This is the last version of EPPlus under the LGPL License (aka free for commercial uses). You can install it using Nuget Package manager: Which library were you using for CSharp?

If you mean library, the older version of EPPlus is still available.

My suggestion would be to avoid using Office Interop. When you use it, it creates a dependency on Office, meaning it has to be installed on the machine in order for your app to run. That's completely unnecessary and wasteful from licensing perspective. There are several packages on Nuget that allow you to work with Excel sheets without the need for Office to be loaded. A couple would be ClosedXML and EPPlus.

I'm a fan of Sylvan.Data.Excel myself

Here is a simple, complete gist showing how to turn a DbDataReader into an HTML table. The WriteHtmlTable extension method can be used with any ADO.NET compatible driver, which the Sylvan.Data.Excel and Sylvan.Data.Csv libraries both support.

I maintain a couple libraries that can help with reading the data files: Sylvan.Data.Csv and Sylvan.Data.Excel. I see no reason to not allow users to provide whichever format is convenient for them.

You can give my library a try: Sylvan.Data.Excel. You seem to be concerned about performance, so you can be happy to know it is the fastest Excel reader in the .NET ecosystem, by quite a wide margin. It is open source, MIT licensed, and is easy to use (in my biased opinion).

The easiest? I'm gonna have to disagree with you on that one. I believe my library, Sylvan.Data.Excel make it even easier (possibly the easiest) to read Excel data in .NET.

If you're trying to load an Excel worksheet into a DataTable, I maintain a library that can make this quite easy: Sylvan.Data.Excel. It is available as a nuget package, open source, MIT licensed, and the fastest Excel reader for .NET.

I maintain a library, Sylvan.Data.Excel that might work for you. I claim it is the fastest Excel library in the .NET ecosystem. It is open source and MIT licensed, so feel free to use it however you wish. It has no external dependencies other than .NET itself.

I would recommend taking a look at [Sylvan.Data.Excel](https://github.com/MarkPflug/Sylvan.Data.Excel) if all you are trying to do is read data out of excel. It is a library that I maintain, and is extremely fast and easy to use.

I maintain a library that you can try: Sylvan.Data.Excel.

Here is a some sample code of how to echo the contents of an Excel spreadsheet as CSV to the client browser using my libraries Sylvan.Data.Excel and Sylvan.Data.Csv: