Reading Excel files from C#


Is there a free or open source library to read Excel files (.xls) directly from a C# program?

It does not need to be too fancy, just to select a worksheet and read the data as strings. So far, I've been using Export to Unicode text function of Excel, and parsing the resulting (tab-delimited) file, but I'd like to eliminate the manual step.

This question is tagged with c# .net excel ms-office

~ Asked on 2008-08-19 07:23:46

32 Answers


var fileName = string.Format("{0}\\fileNameHere", Directory.GetCurrentDirectory());
var connectionString = string.Format("Provider=Microsoft.Jet.OLEDB.4.0; data source={0}; Extended Properties=Excel 8.0;", fileName);

var adapter = new OleDbDataAdapter("SELECT * FROM [workSheetNameHere$]", connectionString);
var ds = new DataSet();

adapter.Fill(ds, "anyNameHere");

DataTable data = ds.Tables["anyNameHere"];

This is what I usually use. It is a little different because I usually stick a AsEnumerable() at the edit of the tables:

var data = ds.Tables["anyNameHere"].AsEnumerable();

as this lets me use LINQ to search and build structs from the fields.

var query = data.Where(x => x.Field<string>("phoneNumber") != string.Empty).Select(x =>
                new MyContact
                        firstName= x.Field<string>("First Name"),
                        lastName = x.Field<string>("Last Name"),
                        phoneNumber =x.Field<string>("Phone Number"),

~ Answered on 2008-08-19 12:18:20


If it is just simple data contained in the Excel file you can read the data via ADO.NET. See the connection strings listed here: or


Update: then you can just read the worksheet via something like select * from [Sheet1$]

~ Answered on 2008-08-19 07:28:37


The ADO.NET approach is quick and easy, but it has a few quirks which you should be aware of, especially regarding how DataTypes are handled.

This excellent article will help you avoid some common pitfalls:

~ Answered on 2008-08-20 13:19:17


This is what I used for Excel 2003:

Dictionary<string, string> props = new Dictionary<string, string>();
props["Provider"] = "Microsoft.Jet.OLEDB.4.0";
props["Data Source"] = repFile;
props["Extended Properties"] = "Excel 8.0";

StringBuilder sb = new StringBuilder();
foreach (KeyValuePair<string, string> prop in props)
string properties = sb.ToString();

using (OleDbConnection conn = new OleDbConnection(properties))
    DataSet ds = new DataSet();
    string columns = String.Join(",", columnNames.ToArray());
    using (OleDbDataAdapter da = new OleDbDataAdapter(
        "SELECT " + columns + " FROM [" + worksheet + "$]", conn))
        DataTable dt = new DataTable(tableName);

~ Answered on 2008-09-04 11:39:19


How about Excel Data Reader?

I've used in it anger, in a production environment, to pull large amounts of data from a variety of Excel files into SQL Server Compact. It works very well and it's rather robust.

~ Answered on 2010-09-08 08:45:52


Here's some code I wrote in C# using .NET 1.1 a few years ago. Not sure if this would be exactly what you need (and may not be my best code :)).

using System;
using System.Data;
using System.Data.OleDb;

namespace ExportExcelToAccess
    /// <summary>
    /// Summary description for ExcelHelper.
    /// </summary>
    public sealed class ExcelHelper
        private const string CONNECTION_STRING = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=<FILENAME>;Extended Properties=\"Excel 8.0;HDR=Yes;\";";

        public static DataTable GetDataTableFromExcelFile(string fullFileName, ref string sheetName)
            OleDbConnection objConnection = new OleDbConnection();
            objConnection = new OleDbConnection(CONNECTION_STRING.Replace("<FILENAME>", fullFileName));
            DataSet dsImport = new DataSet();


                DataTable dtSchema = objConnection.GetOleDbSchemaTable(OleDbSchemaGuid.Tables, null);

                if( (null == dtSchema) || ( dtSchema.Rows.Count <= 0 ) )
                    //raise exception if needed

                if( (null != sheetName) && (0 != sheetName.Length))
                    if( !CheckIfSheetNameExists(sheetName, dtSchema) )
                        //raise exception if needed
                    //Reading the first sheet name from the Excel file.
                    sheetName = dtSchema.Rows[0]["TABLE_NAME"].ToString();

                new OleDbDataAdapter("SELECT * FROM [" + sheetName + "]", objConnection ).Fill(dsImport);
            catch (Exception)
                //raise exception if needed
                // Clean up.
                if(objConnection != null)

            return dsImport.Tables[0];
            #region Commented code for importing data from CSV file.
            //              string strConnectionString = "Provider=Microsoft.Jet.OLEDB.4.0;" +"Data Source=" + System.IO.Path.GetDirectoryName(fullFileName) +";" +"Extended Properties=\"Text;HDR=YES;FMT=Delimited\"";
            //              System.Data.OleDb.OleDbConnection conText = new System.Data.OleDb.OleDbConnection(strConnectionString);
            //              new System.Data.OleDb.OleDbDataAdapter("SELECT * FROM " + System.IO.Path.GetFileName(fullFileName).Replace(".", "#"), conText).Fill(dsImport);
            //              return dsImport.Tables[0];


        /// <summary>
        /// This method checks if the user entered sheetName exists in the Schema Table
        /// </summary>
        /// <param name="sheetName">Sheet name to be verified</param>
        /// <param name="dtSchema">schema table </param>
        private static bool CheckIfSheetNameExists(string sheetName, DataTable dtSchema)
            foreach(DataRow dataRow in dtSchema.Rows)
                if( sheetName == dataRow["TABLE_NAME"].ToString() )
                    return true;
            return false;

~ Answered on 2008-08-19 10:50:55


Koogra is an open-source component written in C# that reads and writes Excel files.

~ Answered on 2008-11-04 11:22:57


While you did specifically ask for .xls, implying the older file formats, for the OpenXML formats (e.g. xlsx) I highly recommend the OpenXML SDK (

~ Answered on 2008-09-04 06:00:46


I did a lot of reading from Excel files in C# a while ago, and we used two approaches:

  • The COM API, where you access Excel's objects directly and manipulate them through methods and properties
  • The ODBC driver that allows to use Excel like a database.

The latter approach was much faster: reading a big table with 20 columns and 200 lines would take 30 seconds via COM, and half a second via ODBC. So I would recommend the database approach if all you need is the data.



~ Answered on 2008-08-20 13:24:35


I want to show a simple method to read xls/xlsx file with .NET. I hope that the following will be helpful for you.

 private DataTable ReadExcelToTable(string path)    

     //Connection String

     string connstring = "Provider=Microsoft.ACE.OLEDB.12.0;Data Source=" + path + ";Extended Properties='Excel 8.0;HDR=NO;IMEX=1';";  
     //the same name 
     //string connstring = Provider=Microsoft.JET.OLEDB.4.0;Data Source=" + path + //";Extended Properties='Excel 8.0;HDR=NO;IMEX=1';"; 

     using(OleDbConnection conn = new OleDbConnection(connstring))
        //Get All Sheets Name
        DataTable sheetsName = conn.GetOleDbSchemaTable(OleDbSchemaGuid.Tables,new object[]{null,null,null,"Table"});  

        //Get the First Sheet Name
        string firstSheetName = sheetsName.Rows[0][2].ToString(); 

        //Query String 
        string sql = string.Format("SELECT * FROM [{0}]",firstSheetName); 
        OleDbDataAdapter ada =new OleDbDataAdapter(sql,connstring);
        DataSet set = new DataSet();
        return set.Tables[0];   

Code is from article: You can get more details from it.

~ Answered on 2012-03-06 08:49:41


ExcelMapper is an open source tool ( that can be used to read Excel worksheets as Strongly Typed Objects. It supports both xls and xlsx formats.

~ Answered on 2009-05-11 15:26:26


Not free, but with the latest Office there's a very nice automation .Net API. (there has been an API for a long while but was nasty COM) You can do everything you want / need in code all while the Office app remains a hidden background process.

~ Answered on 2008-08-19 07:31:57


SpreadsheetGear for .NET is an Excel compatible spreadsheet component for .NET. You can see what our customers say about performance on the right hand side of our product page. You can try it yourself with the free, fully-functional evaluation.

~ Answered on 2009-01-19 15:49:51


Forgive me if I am off-base here, but isn't this what the Office PIA's are for?

~ Answered on 2008-08-19 07:28:03


The .NET component Excel Reader .NET may satisfy your requirement. It's good enought for reading XLSX and XLS files. So try it from:

~ Answered on 2011-04-12 07:30:55


Lately, partly to get better at LINQ.... I've been using Excel's automation API to save the file as XML Spreadsheet and then get process that file using LINQ to XML.

~ Answered on 2008-09-04 11:10:40


SmartXLS is another excel spreadsheet component which support most features of excel Charts,formulas engines, and can read/write the excel2007 openxml format.

~ Answered on 2009-09-30 03:18:16


I recommend the FileHelpers Library which is a free and easy to use .NET library to import/export data from EXCEL, fixed length or delimited records in files, strings or streams + More.

The Excel Data Link Documentation Section

~ Answered on 2008-09-04 10:24:13


You can try using this open source solution that makes dealing with Excel a lot more cleaner.

~ Answered on 2010-03-09 00:16:47


SpreadsheetGear is awesome. Yes it's an expense, but compared to twiddling with these other solutions, it's worth the cost. It is fast, reliable, very comprehensive, and I have to say after using this product in my fulltime software job for over a year and a half, their customer support is fantastic!

~ Answered on 2010-08-26 18:01:25


Late to the party, but I'm a fan of LinqToExcel

~ Answered on 2012-10-26 15:09:52


The solution that we used, needed to:

  • Allow Reading/Writing of Excel produced files
  • Be Fast in performance (not like using COMs)
  • Be MS Office Independent (needed to be usable without clients having MS Office installed)
  • Be Free or Open Source (but actively developed)

There are several choices, but we found NPoi (.NET port of Java's long existing Poi open source project) to be the best:

It also allows working with .doc and .ppt file formats

~ Answered on 2011-04-21 10:07:48


If it's just tabular data. I would recommend file data helpers by Marcos Melli which can be downloaded here.

~ Answered on 2011-09-13 04:47:14


you could write an excel spreadsheet that loads a given excel spreadsheet and saves it as csv (rather than doing it manually).

then you could automate that from c#.

and once its in csv, the c# program can grok that.

(also, if someone asks you to program in excel, it's best to pretend you don't know how)

(edit: ah yes, rob and ryan are both right)

~ Answered on 2008-08-19 07:26:38


I know that people have been making an Excel "extension" for this purpose.
You more or less make a button in Excel that says "Export to Program X", and then export and send off the data in a format the program can read. should be a good place to start.

Good luck

~ Answered on 2008-08-19 07:26:41


Just did a quick demo project that required managing some excel files. The .NET component from GemBox software was adequate for my needs. It has a free version with a few limitations.

~ Answered on 2008-08-19 07:48:58


We use ClosedXML in rather large systems.

  • Free
  • Easy to install
  • Straight forward coding
  • Very responsive support
  • Developer team is extremly open to new suggestions. Often new features and bug fixes are implemented within the same week

~ Answered on 2012-08-17 08:34:36

1 Spreadsheet will do this work for you, and at no charge. Just take a look at this.

~ Answered on 2011-09-15 03:33:19


Excel Package is an open-source (GPL) component for reading/writing Excel 2007 files. I used it on a small project, and the API is straightforward. Works with XLSX only (Excel 200&), not with XLS.

The source code also seems well-organized and easy to get around (if you need to expand functionality or fix minor issues as I did).

At first, I tried the ADO.Net (Excel connection string) approach, but it was fraught with nasty hacks -- for instance if second row contains a number, it will return ints for all fields in the column below and quietly drop any data that doesn't fit.

~ Answered on 2009-10-01 03:44:08


Excel Data Reader is the way to go!

It´s Open Source, at and actively developed.

We been using it for reading Tabular (and sometimes not so tabular) worksheets for a couple of years now (In a financial application).

Works like a charm to read unit test data from human-readable sheets.

Just avoid the feature of trying to return DateTime's, as, for Excel, DateTime's are just double numbers.

~ Answered on 2011-02-04 19:41:51


I just used ExcelLibrary to load an .xls spreadsheet into a DataSet. Worked great for me.

~ Answered on 2009-08-24 06:21:56


If you have multiple tables in the same worksheet you can give each table an object name and read the table using the OleDb method as shown here:

~ Answered on 2011-07-20 02:33:05

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