Stack OverflowHow do I create an Excel (.XLS and .XLSX) file in C# without installing Microsoft Office?
[+1941] [44] mistrmark
[2008-09-29 22:30:28]
[ c# .net excel file-io ]
[ ]

How can I create an Excel spreadsheet with C# without requiring Excel to be installed on the machine that's running the code?

(43) @Mike The "without requiring Excel to be installed" piece has nothing to do with being professional. It's about dependencies. The original text of the question was worded as: "Ideally, I would like open source so I don't have to add any third party dependencies to my code, and I would like to avoid using Excel directly to create the file (using OLE Automation.)" It's unfortunate the question was drastically simplified. - Tony
(6) Assuming you were trying to do something sans library or external code, I can't speak for xls file, but for xlsx files, why not start by taking an existing one, renaming it to a zip file and exploring the contents? A little bit of reverse engineering will tell you quite a bit. There are several different xml files and rels files in the various folders and subfolders. Try exploring that and see if it's something you can replicate or see if you can find documentation on the various xml namespaces/schemas. - Alexander Ryan Baggett
[+1086] [2010-04-08 21:36:03] Mike Webb [ACCEPTED]

You can use a library called ExcelLibrary. It's a free, open source library posted on Google Code:

ExcelLibrary [1]

This looks to be a port of the PHP ExcelWriter that you mentioned above. It will not write to the new .xlsx format yet, but they are working on adding that functionality in.

It's very simple, small and easy to use. Plus it has a DataSetHelper that lets you use DataSets and DataTables to easily work with Excel data.

ExcelLibrary seems to still only work for the older Excel format (.xls files), but may be adding support in the future for newer 2007/2010 formats.

You can also use EPPlus [2], which works only for Excel 2007/2010 format files (.xlsx files). There's also NPOI [3] which works with both.

There are a few known bugs with each library as noted in the comments. In all, EPPlus seems to be the best choice as time goes on. It seems to be more actively updated and documented as well.

Also, as noted by @АртёмЦарионов below, EPPlus has support for Pivot Tables and ExcelLibrary may have some support ( Pivot table issue in ExcelLibrary [4])

Here are a couple links for quick reference:
ExcelLibrary [5] - GNU Lesser GPL [6]
EPPlus [7] - GNU (LGPL) - No longer maintained [8]
EPPlus 5 [9] - Polyform Noncommercial - Starting May 2020 [10]
NPOI [11] - Apache License [12]

Here some example code for ExcelLibrary:

Here is an example taking data from a database and creating a workbook from it. Note that the ExcelLibrary code is the single line at the bottom:

//Create the data set and table
DataSet ds = new DataSet("New_DataSet");
DataTable dt = new DataTable("New_DataTable");

//Set the locale for each
ds.Locale = System.Threading.Thread.CurrentThread.CurrentCulture;
dt.Locale = System.Threading.Thread.CurrentThread.CurrentCulture;

//Open a DB connection (in this example with OleDB)
OleDbConnection con = new OleDbConnection(dbConnectionString);

//Create a query and fill the data table with the data from the DB
string sql = "SELECT Whatever FROM MyDBTable;";
OleDbCommand cmd = new OleDbCommand(sql, con);
OleDbDataAdapter adptr = new OleDbDataAdapter();

adptr.SelectCommand = cmd;

//Add the table to the data set

//Here's the easy part. Create the Excel worksheet from the data set
ExcelLibrary.DataSetHelper.CreateWorkbook("MyExcelFile.xls", ds);

Creating the Excel file is as easy as that. You can also manually create Excel files, but the above functionality is what really impressed me.


(248) ExcelLibrary has been superseded by the exceptional EPPlus - Jan updates it regularly. Have been using it and it is one of the finest open source projects we've worked with. - Mark A
(3) It should be noted that ExcelLibrary has a lot of performance issues when dealing with large datasets(larger than 5000 rows with lots of columns). Currently doing a heavy modification of the code base at work so we can use it in a project. - rossisdead
EPPlus seems far less buggy than ExcelLibrary, BUT it is GPL and therefore only a solution for open source projects. - Seth
EPPlus is actually still technically GPL because it is a derived work (i.e. the code base is still based off of ExcelLibrary, and since that is GPL so is EPPlus ... you can't make some changes to GPL code and slap a LGPL license on it). Does anyone know of a way to write to Excel using either commercial code or true LGPL (or similarly licensed code). - Beep beep
ExcelLibrary doesn't work anymore. If you want to write Excel 2003 files (.xls) this library is working great: CSharpJExcel Make sure to download the C# port. - Chris
(8) What about ClosedXML? I may prove to be useful in your projects. - Amadeus Sánchez
I tried ExcelLibrary, all it could do was produce a 'corrupted file', nothing fancy just 3 columns, small file. Excel 2016 wouldn't open. Tried the automatic file generation rom DataTable. - Vega4
EPPlus is LGPL up to version 5. If you use version 5 or above in your code, an exception will be thrown if you do not have a license key. - Britt Kelly
[+601] [2010-03-29 12:25:54] Jan Källman

If you are happy with the xlsx format, try my GitHub project, EPPlus [1]. It started with the source from ExcelPackage, but today it's a total rewrite. It supports ranges, cell styling, charts, shapes, pictures, named ranges, AutoFilter and a lot of other stuff.


(78) License is now LGPL, release notes here: - Simon D
(13) The examples were helpful. I was able to change my code from using Microsoft interop library (horribly slow) to this library (version 4.x) in a couple hours. My benchmark writes a file with two tabs and about 750,000 cells. Using MS interop it took 13 minutes. Using EPPlus it took 10 seconds, a roughly 80x speedup. Very happy! - Paul Chernoch
@JanKällman You should update your CodePlex page to show you've got these methods available: LoadFromCollection<T>, LoadFromDataTable etc. (found via here) - PeterX
(3) For clarity in this thread, the LGPL allows the software to be linked to without the infective part of the GPL occuring. You only need to open source changes you make to ClosedXml or if you directly put the source code (as opposed to referencing the ClosedXml assemblies) inside of your application then you need to open source your application. - Chris Marisic
(6) @Paul Chernoch: We populate large Excel sheets with interop very quickly. The secret is to do a bulk update. Create a object [,] block, populate that, then write that matrix to Excel at one time: excelWorksheet.get_Range(range).Value2 = block; - Marc Meketon
(7) Looks like the licensing is moving from LGPL to Polyform Noncommercial 1.0.0 license - Luke
[+181] [2011-08-16 09:25:58] Pellared

And what about using Open XML SDK 2.0 for Microsoft Office?

A few benefits:

  • Doesn't require Office installed
  • Made by Microsoft = decent MSDN documentation
  • Just one .Net dll to use in project
  • SDK comes with many tools like diff, validator, etc



(3) Important to note that the DLL for this is just over 5 MB and limited to Office 2007 formats. But certainly the easiest and fastest solution which works for me. - Josh Brown
(18) Just a heads up that v2.5 is out and can be downloaded here. - Snuffleupagus
(10) The SDK models the XML into classes, so that each XML tag is mapped to a tag, and then you have to build the class hierarchy (each instance has a collection of child instances/tags) correctly. This means you have to know the XML structure of an Excel file, which is very complicated. It's much easier to use a wrapper such as EPPlus, mentioned above, which simplifies things. - Tsahi Asher
(2) A great sample of Microsoft Open XML SDK - Open XML Writer can be found at… Or see Stack Overflow solution… - Greg
(4) I found Microsoft Open XML SDK's Open XML Writer to be great. Using the solutions above, (Especially Vincent Tom's sample (Poly Math)), it's easy to build a writer that streams through big sets of data, and writes records in a manner similiar and not too much more complex to what you'd do for CSV; but that you're instead writing xml. Open XML is the mindset that Microsoft considers it's new Office formats in. And you can always rename them from .xslx to .zip files if you feel like poking at their XML contents. - Greg
(1) Please note that Open XML SDK are now open source and hosted on github. Also you don't need to install the SDK, just fire-up nuget and DocumentFormat.OpenXml is all you need. It works with .net standard 1.3. - horeaper
How interesting it was and your answer made me learn this. I have just entered the field of programming and such content is interesting to me. - elnaz jangi
[+169] [2009-06-20 20:48:26] Leniel Maccaferri

I've used with success the following open source projects:

  • ExcelPackage for OOXML formats (Office 2007)

  • NPOI for .XLS format (Office 2003). NPOI 2.0 [1] (Beta) also supports XLSX.

Take a look at my blog posts:

Creating Excel spreadsheets .XLS and .XLSX in C# [2]

NPOI with Excel Table and dynamic Chart [3]


(6) A note on NPOI - Row and Column references are zero-based. Does work well for populating an existing template. - John M
[+111] [2008-09-29 22:41:09] Panos

You can use OLEDB to create and manipulate Excel files. Check this: Reading and Writing Excel using OLEDB [1].

Typical example:

using (OleDbConnection conn = new OleDbConnection("Provider=Microsoft.Jet.OLEDB.4.0;Data Source=C:\\temp\\test.xls;Extended Properties='Excel 8.0;HDR=Yes'"))
  OleDbCommand cmd = new OleDbCommand("CREATE TABLE [Sheet1] ([Column1] string, [Column2] string)", conn);

EDIT - Some more links:


(4) Can someone confirm if this works when running in x64? I am pretty sure Jet only works if your app is compiled or running in 32-bit mode. - Lamar
(2) I've just tested this connection and it failed on a Windows Server 2008 R2 x64 RC, seems like one have to install the 2007 Office System Driver: Data Connectivity Components [… - Chris Richner
(25) Be very careful with this -- it's a big ugly cludge (for example, sometimes it guesses a column type and discards all the data that does not fit). - dbkk
(9) One should be very careful if using this method. I've found it very flaky for data that isn't in a perfect format. - Kenny Mann
(9) As a person who had to use OleDb in a big project, I say STAY AWAY FROM IT! It sometimes is not able to retrieve a cell value just because it couldn't understand the format. It doesn't have a delete operation. It works totally different and unpredictable even with a slightest provider change. I'd say go for a proven commercial solution. - Caner Öncü
(1) Microsoft has upgraded Jet, try this link… - Justin
(2) At a previous job, we used Microsoft Access Database Engine 2010 Redistributable. It took the form of an OLEDB driver that allowed reading from and writing to Excel files, as well as Access format files. Note that this download does not require you to install the entire Office suite. Note also that it comes in both 32-bit and 64-bit flavors. It is very important that you match the 32-bit or 64-bit version to the architecture of the host process that will access the file(s). In our case, the host process was SSIS. - Stephen G Tuggy
[+81] [2009-01-24 18:33:17] Joe Erickson

The commercial solution, SpreadsheetGear for .NET [1] will do it.

You can see live ASP.NET (C# and VB) samples here [2] and download an evaluation version here [3].

Disclaimer: I own SpreadsheetGear LLC


(10) You have a great product but I think a lot of people here are expecting free solutions. That might explain the down votes. - md1337
[+66] [2009-06-01 15:45:06] Nate

A few options I have used:

If XLSX is a must: ExcelPackage [1] is a good start but died off when the developer quit working on it. ExML picked up from there and added a few features. ExML [2] isn't a bad option, I'm still using it in a couple of production websites.

For all of my new projects, though, I'm using NPOI [3], the .NET port of Apache POI [4]. NPOI 2.0 (Alpha) [5] also supports XLSX.


Be careful with ExcelPackage if you need to support XLS. I had a hard time with it and eventually switched to ExcelLibrary. - Jeremy
Definitely true. ExcelPackage/ExML is only a good option if you need the XLSX support. - Nate
(5) Note that ExcelPackage has a successor: EPPlus ( which supports XLSX. My only concern, compared to NPOI for example, is performance, e.g. when there is a lot of columns. - Pragmateek
[+64] [2008-09-29 22:37:59] Forgotten Semicolon

An extremely lightweight option may be to use HTML tables. Just create head, body, and table tags in a file, and save it as a file with an .xls extension. There are Microsoft specific attributes that you can use to style the output, including formulas.

I realize that you may not be coding this in a web application, but here is an example [1] of the composition of an Excel file via an HTML table. This technique could be used if you were coding a console app, desktop app, or service.


(6) It's so ad hoc but it works (not to mention excel issuing a warning on opening) and is so simple, it deserves to have a place as a solution. Though only for showing that you can export an excel file :)) - Luka Ramishvili
(3) This solution worked fine for me, just note you cannot use .xlsx extension - Jill
Some people at my organization can't open excel files made this way in Office 2010 and above. Don't know what the problem is, but I had to roll my own OpenXML implementation. (see Sogger's answer) - Kristen Hammack
[+52] [2010-11-23 16:33:00] Manuel

If you're creating Excel 2007/2010 files give this open source project a try:

It provides an object oriented way to manipulate the files (similar to VBA) without dealing with the hassles of XML Documents. It can be used by any .NET language like C# and Visual Basic (VB).

ClosedXML allows you to create Excel 2007/2010 files without the Excel application. The typical example is creating Excel reports on a web server:

var workbook = new XLWorkbook();
var worksheet = workbook.Worksheets.Add("Sample Sheet");
worksheet.Cell("A1").Value = "Hello World!";

(9) I tried using this in a project that builds pretty large Excel sheets. Excellent library, but extremely poor in performance. I just did a comparison for the project I'm working on: ClosedXML (v 0.53.3) took 92,489 ms whereas EPPlus (v 2.9.03, for testing - we can't use because it's GPL) took 16,500 ms. - Druid
(1) @Druid the license is LGPL assuming you don't modify the source code to ClosedXML it is free to use - Chris Marisic
[+49] [2008-09-29 22:34:23] GEOCHET

You actually might want to check out the interop classes available in C# (e.g. Microsoft.Office.Interop.Excel. You say no OLE (which this isn't), but the interop classes are very easy to use. Check out the C# Documentation here [1] (Interop for Excel starts on page 1072 of the C# PDF).

You might be impressed if you haven't tried them.

Please be warned of Microsoft's stance [2] on this:

Microsoft does not currently recommend, and does not support, Automation of Microsoft Office applications from any unattended, non-interactive client application or component (including ASP, ASP.NET, DCOM, and NT Services), because Office may exhibit unstable behavior and/or deadlock when Office is run in this environment.


(6) But you have to make sure that you dispose of everything manually, otherwise you will leak memory - MagicKat
(8) @Ricky B: Also, in my experience with the interop is that it does use excel. Every time we used it, if Excel wasn't installed on the machine, we would get COM exceptions. - MagicKat
(1) With the OLE, even with very careful disposals, it eventually leaks memory or crashes. This is argueably OK for attended applications/ workstations, but for servers is not recommended (MS has a KB stating this). For our server, we just reboot it nightly. Again, that works OK. - Jennifer Zouak
(11) @Geoffrey: ah OK you are going to make me work for it :) --> Microsoft does not currently recommend, and does not support, Automation of Microsoft Office applications from any unattended, non-interactive client application... - Jennifer Zouak
(4) I'm coming to this discussion after struggling more than a week on interop, and unless your needs are very simple, this is not gonna work. The support for formatting your spreadsheet is abysmal, which is arguably the reason for generating an .xls file and not just a flat .csv file. For example, have you tried outputting more than 911 characters in a cell, or have you tried setting the width of merged cells in a consistent manner? I have, and I can't tell you how much I hate this crap now... Do yourself a favor and go with one of the free libraries mentioned on this discussion. - md1337
I haven't changed Interop for EPPlus yet (but already on the half way) so I don't really know how much better life is with it, but dealing with Interop I got so much pain in very surprising cases nearly every time I needed something more complex than just create .xls/.xlsx file with simple table inside. And mentioned above 'twice-check-to-dispose-everything-magic' is one of that everyday pain. But yeah, it works, and most of the time it's enough. - pkuderov
(1) Warning the Microsoft.Office.Interops library has a dependency on Excel being installed. Thus does not answer the user's question - Mark
(1) He literally says he does not want to have to install office - JSON
[+49] [2009-02-12 15:04:46] Petr Snobelt

You can use ExcelXmlWriter [1].

It works fine.


[+35] [2011-12-05 12:08:36] Mike Gledhill

Here's a completely free C# library, which lets you export from a DataSet, DataTable or List<> into a genuine Excel 2007 .xlsx file, using the OpenXML libraries:

Full source code is provided - free of charge - along with instructions, and a demo application.

After adding this class to your application, you can export your DataSet to Excel in just one line of code:

CreateExcelFile.CreateExcelDocument(myDataSet, "C:\\Sample.xlsx");

It doesn't get much simpler than that...

And it doesn't even require Excel to be present on your server.

(1) This seems a bit misleading, as you are asking for a donation to get all of the features. - UrbanEsc
(1) That's partly true: The completely free version will generate a perfect .xlsx file for you, and all source code is provided. If you donate $10 or more to one of those two charities (of which I receive absolutely nothing), then you get a "better" version showing how to do formatting, dates, etc. Given the cost of third-party products, I reckon donating $10 to a good cause instead is well worth it ! - Mike Gledhill
[+26] [2008-09-30 01:16:40] Sam Warwick

You could consider creating your files using the XML Spreadsheet 2003 [1] format. This is a simple XML format using a well documented schema [2].


[+23] [2008-09-29 22:48:00] ManiacZX

You may want to take a look at GemBox.Spreadsheet [1].

They have a free version with all features but limited to 150 rows per sheet and 5 sheets per workbook, if that falls within your needs.

I haven't had need to use it myself yet, but does look interesting.


[+21] [2016-10-07 18:03:31] Davis Jebaraj

Syncfusion Essential XlsIO [1] can do this. It has no dependency on Microsoft office and also has specific support for different platforms.

Code sample:

//Creates a new instance for ExcelEngine.
ExcelEngine excelEngine = new ExcelEngine();
//Loads or open an existing workbook through Open method of IWorkbooks
IWorkbook workbook = excelEngine.Excel.Workbooks.Open(fileName);
//To-Do some manipulation|
//To-Do some manipulation
//Set the version of the workbook.
workbook.Version = ExcelVersion.Excel2013;
//Save the workbook in file system as xlsx format

The whole suite of controls is available for free through the community license [6] program if you qualify (less than 1 million USD in revenue). Note: I work for Syncfusion.


[+18] [2009-11-10 05:05:23] Dimi Takis


you can also use a third party library like Aspose [1].

This library has the benefit that it does not require Excel to be installed on your machine which would be ideal in your case.


To be more precise, you can use Aspose.Cells for .NET in order to create Excel (XLS, XLSX) files in your .NET application. - Shahzad Latif
(9) Yes you can, if you don't mind paying a minimum license fee of $999. Try the MikesKnowledgeBase library... which is $999 cheaper than this !! - Mike Gledhill
[+17] [2008-11-24 08:22:41] biozinc

The various Office 2003 XML libraries avaliable work pretty well for smaller excel files. However, I find the sheer size of a large workbook saved in the XML format to be a problem. For example, a workbook I work with that would be 40MB in the new (and admittedly more tightly packed) XLSX format becomes a 360MB XML file.

As far as my research has taken me, there are two commercial packages that allow output to the older binary file formats. They are:

Neither are cheap (500USD and 800USD respectively, I think). but both work independant of Excel itself.

What I would be curious about is the Excel output module for the likes of I wonder if they can be ported from Java to .Net.


This one works on both .net and java,and is not expensive. SmartXLS - liya
[+17] [2015-12-02 13:30:28] Sachin Dhir

OpenXML is also a good alternative that helps avoid installing MS Excel on Server.The Open XML SDK 2.0 provided by Microsoft simplifies the task of manipulating Open XML packages and the underlying Open XML schema elements within a package. The Open XML Application Programming Interface (API) encapsulates many common tasks that developers perform on Open XML packages.

Check this out OpenXML: Alternative that helps avoid installing MS Excel on Server [1]


[+15] [2008-09-30 03:53:10] Aaron Powell

I agree about generating XML Spreadsheets, here's an example on how to do it for C# 3 (everyone just blogs about it in VB 9 :P)

[+15] [2009-02-15 08:12:37] EMP

I've just recently used FlexCel.NET [1] and found it to be an excellent library! I don't say that about too many software products. No point in giving the whole sales pitch here, you can read all the features on their website.

It is a commercial product, but you get the full source if you buy it. So I suppose you could compile it into your assembly if you really wanted to. Otherwise it's just one extra assembly to xcopy - no configuration or installation or anything like that.

I don't think you'll find any way to do this without third-party libraries as .NET framework, obviously, does not have built in support for it and OLE Automation is just a whole world of pain.


[+15] [2015-07-23 07:55:17] Harsha.Vaswani

I have written a simple code to export dataset to excel without using excel object by using System.IO.StreamWriter.

Below is the code which will read all tables from dataset and write them to sheets one by one. I took help from this article [1].

public static void exportToExcel(DataSet source, string fileName)
        const string endExcelXML = "</Workbook>";
        const string startExcelXML = "<xml version>\r\n<Workbook " +
                 "xmlns=\"urn:schemas-microsoft-com:office:spreadsheet\"\r\n" +
                 " xmlns:o=\"urn:schemas-microsoft-com:office:office\"\r\n " +
                 "xmlns:x=\"urn:schemas-    microsoft-com:office:" +
                 "excel\"\r\n xmlns:ss=\"urn:schemas-microsoft-com:" +
                 "office:spreadsheet\">\r\n <Styles>\r\n " +
                 "<Style ss:ID=\"Default\" ss:Name=\"Normal\">\r\n " +
                 "<Alignment ss:Vertical=\"Bottom\"/>\r\n <Borders/>" +
                 "\r\n <Font/>\r\n <Interior/>\r\n <NumberFormat/>" +
                 "\r\n <Protection/>\r\n </Style>\r\n " +
                 "<Style ss:ID=\"BoldColumn\">\r\n <Font " +
                 "x:Family=\"Swiss\" ss:Bold=\"1\"/>\r\n </Style>\r\n " +
                 "<Style     ss:ID=\"StringLiteral\">\r\n <NumberFormat" +
                 " ss:Format=\"@\"/>\r\n </Style>\r\n <Style " +
                 "ss:ID=\"Decimal\">\r\n <NumberFormat " +
                 "ss:Format=\"0.0000\"/>\r\n </Style>\r\n " +
                 "<Style ss:ID=\"Integer\">\r\n <NumberFormat " +
                 "ss:Format=\"0\"/>\r\n </Style>\r\n <Style " +
                 "ss:ID=\"DateLiteral\">\r\n <NumberFormat " +
                 "ss:Format=\"mm/dd/yyyy;@\"/>\r\n </Style>\r\n " +
                 "</Styles>\r\n ";
        System.IO.StreamWriter excelDoc = null;
        excelDoc = new System.IO.StreamWriter(fileName);

        int sheetCount = 1;
        foreach (DataTable table in source.Tables)
            int rowCount = 0;
            excelDoc.Write("<Worksheet ss:Name=\"" + table.TableName + "\">");
            for (int x = 0; x < table.Columns.Count; x++)
                excelDoc.Write("<Cell ss:StyleID=\"BoldColumn\"><Data ss:Type=\"String\">");
            foreach (DataRow x in table.Rows)
                //if the number of rows is > 64000 create a new page to continue output
                if (rowCount == 64000)
                    rowCount = 0;
                    excelDoc.Write(" </Worksheet>");
                    excelDoc.Write("<Worksheet ss:Name=\"" + table.TableName + "\">");
                excelDoc.Write("<Row>"); //ID=" + rowCount + "
                for (int y = 0; y < table.Columns.Count; y++)
                    System.Type rowType;
                    rowType = x[y].GetType();
                    switch (rowType.ToString())
                        case "System.String":
                            string XMLstring = x[y].ToString();
                            XMLstring = XMLstring.Trim();
                            XMLstring = XMLstring.Replace("&", "&");
                            XMLstring = XMLstring.Replace(">", ">");
                            XMLstring = XMLstring.Replace("<", "<");
                            excelDoc.Write("<Cell ss:StyleID=\"StringLiteral\">" +
                                           "<Data ss:Type=\"String\">");
                        case "System.DateTime":
                            //Excel has a specific Date Format of YYYY-MM-DD followed by  
                            //the letter 'T' then hh:mm:sss.lll Example 2005-01-31T24:01:21.000
                            //The Following Code puts the date stored in XMLDate 
                            //to the format above
                            DateTime XMLDate = (DateTime)x[y];
                            string XMLDatetoString = ""; //Excel Converted Date
                            XMLDatetoString = XMLDate.Year.ToString() +
                                 "-" +
                                 (XMLDate.Month < 10 ? "0" +
                                 XMLDate.Month.ToString() : XMLDate.Month.ToString()) +
                                 "-" +
                                 (XMLDate.Day < 10 ? "0" +
                                 XMLDate.Day.ToString() : XMLDate.Day.ToString()) +
                                 "T" +
                                 (XMLDate.Hour < 10 ? "0" +
                                 XMLDate.Hour.ToString() : XMLDate.Hour.ToString()) +
                                 ":" +
                                 (XMLDate.Minute < 10 ? "0" +
                                 XMLDate.Minute.ToString() : XMLDate.Minute.ToString()) +
                                 ":" +
                                 (XMLDate.Second < 10 ? "0" +
                                 XMLDate.Second.ToString() : XMLDate.Second.ToString()) +
                            excelDoc.Write("<Cell ss:StyleID=\"DateLiteral\">" +
                                         "<Data ss:Type=\"DateTime\">");
                        case "System.Boolean":
                            excelDoc.Write("<Cell ss:StyleID=\"StringLiteral\">" +
                                        "<Data ss:Type=\"String\">");
                        case "System.Int16":
                        case "System.Int32":
                        case "System.Int64":
                        case "System.Byte":
                            excelDoc.Write("<Cell ss:StyleID=\"Integer\">" +
                                    "<Data ss:Type=\"Number\">");
                        case "System.Decimal":
                        case "System.Double":
                            excelDoc.Write("<Cell ss:StyleID=\"Decimal\">" +
                                  "<Data ss:Type=\"Number\">");
                        case "System.DBNull":
                            excelDoc.Write("<Cell ss:StyleID=\"StringLiteral\">" +
                                  "<Data ss:Type=\"String\">");
                            throw (new Exception(rowType.ToString() + " not handled."));
            excelDoc.Write(" </Worksheet>");


(1) Like the article says though, that's XML that Excel will read rather than actually being an XLS file, which means that it might only work in Excel and not other programs that read spreadsheets. But it's probably better than the equivalent HTML table answers here! - Rup
Supports xlsx ? OpenXML ? - Kiquenet
[+14] [2011-08-23 16:52:27] Eisbaer

Just want to add another reference to a third party solution that directly addresses your issue:

(Disclaimer: I work for SoftArtisans, the company that makes OfficeWriter)

[+13] [2008-09-29 22:39:50] MagicKat

IKVM [1] + POI [2]

Or, you could use the Interop ...


[+12] [2008-09-30 01:39:05] Ryan Lundy

Here's a way to do it with LINQ to XML, complete with sample code:

Quickly Import and Export Excel Data with LINQ to XML [1]

It's a little complex, since you have to import namespaces and so forth, but it does let you avoid any external dependencies.

(Also, of course, it's VB .NET, not C#, but you can always isolate the VB .NET stuff in its own project to use XML Literals, and do everything else in C#.)


[+12] [2010-12-03 19:53:12] user529824

You can create nicely formatted Excel files using this library:
See below sample:

using (ExcelHelper helper = new ExcelHelper(TEMPLATE_FILE_NAME, GENERATED_FILE_NAME))
    helper.Direction = ExcelHelper.DirectionType.TOP_TO_DOWN;
    helper.CurrentSheetName = "Sheet1";
    helper.CurrentPosition = new CellRef("C3");

    //the template xlsx should contains the named range "header"; use the command "insert"/"name".

    //the template xlsx should contains the named range "sample1";
    //inside this range you should have cells with these values:
    //<name> , <value> and <comment>, which will be replaced by the values from the getSample()
    CellRangeTemplate sample1 = helper.CreateCellRangeTemplate("sample1", new List<string> {"name", "value", "comment"}); 
    helper.InsertRange(sample1, getSample());

    //you could use here other named ranges to insert new cells and call InsertRange as many times you want, 
    //it will be copied one after another;
    //even you can change direction or the current cell/sheet before you insert

    //typically you put all your "template ranges" (the names) on the same sheet and then you just delete it

where sample look like this:

private IEnumerable<List<object>> getSample()
    var random = new Random();

    for (int loop = 0; loop < 3000; loop++)
        yield return new List<object> {"test", DateTime.Now.AddDays(random.NextDouble()*100 - 50), loop};

[+12] [2011-02-16 11:47:30] Simen S

Some 3rd party component vendors like Infragistics or Syncfusion provide very good Excel export capabilities that do not require Microsoft Excel to be installed.

Since these vendors also provide advanced UI grid components, these components are particularly handy if you want the style and layout of an excel export to mimic the current state of a grid in the user interface of your application.

If your export is intended to be executed server side with emphasis on the data to be exported and with no link to the UI, then I would go for one of the free open source options (e.g. ExcelLibrary).

I have previously been involved with projects that attempted to use server side automation on the Microsoft Office suite. Based on this experience I would strongly recommend against that approach.

[+12] [2011-04-28 10:40:05] Gaurav
public class GridViewExportUtil
    public static void Export(string fileName, GridView gv)
            "content-disposition", string.Format("attachment; filename={0}", fileName));
        HttpContext.Current.Response.ContentType = "application/ms-excel";

        using (StringWriter sw = new StringWriter())
            using (HtmlTextWriter htw = new HtmlTextWriter(sw))
                //  Create a form to contain the grid
                Table table = new Table();

                //  add the header row to the table
                if (gv.HeaderRow != null)

                //  add each of the data rows to the table
                foreach (GridViewRow row in gv.Rows)

                //  add the footer row to the table
                if (gv.FooterRow != null)

                //  render the table into the htmlwriter

                //  render the htmlwriter into the response

    /// <summary>
    /// Replace any of the contained controls with literals
    /// </summary>
    /// <param name="control"></param>
    private static void PrepareControlForExport(Control control)
        for (int i = 0; i < control.Controls.Count; i++)
            Control current = control.Controls[i];
            if (current is LinkButton)
                control.Controls.AddAt(i, new LiteralControl((current as LinkButton).Text));
            else if (current is ImageButton)
                control.Controls.AddAt(i, new LiteralControl((current as ImageButton).AlternateText));
            else if (current is HyperLink)
                control.Controls.AddAt(i, new LiteralControl((current as HyperLink).Text));
            else if (current is DropDownList)
                control.Controls.AddAt(i, new LiteralControl((current as DropDownList).SelectedItem.Text));
            else if (current is CheckBox)
                control.Controls.AddAt(i, new LiteralControl((current as CheckBox).Checked ? "True" : "False"));

            if (current.HasControls())

Hi this solution is to export your grid view to your excel file it might help you out

(7) No, this generates HTML marked as an Excel file rather than a true Excel file. Yes, Excel itself will open that OK but other programs that consume spreadsheets - including Microsoft's free Excel viewer, for example - won't accept it. You'd do better to create a real Excel file using one of the libraries here. - Rup
You should also use System.Net.Mime.ContentDisposition to generate the content-disposition header text rather than a string append - that'll cope with filenames that contains spaces etc. correctly. - Rup
[+11] [2017-02-27 23:30:08] Taterhead

The simplest and fastest way to create an Excel file from C# is to use the Open XML Productivity Tool. The Open XML Productivity Tool comes with the Open XML SDK installation. The tool reverse engineers any Excel file into C# code. The C# code can then be used to re-generate that file.

An overview of the process involved is:

  1. Install the Open XML SDK with the tool.
  2. Create an Excel file using the latest Excel client with desired look. Name it DesiredLook.xlsx.
  3. With the tool open DesiredLook.xlsx and click the Reflect Code button near the top. enter image description here
  4. The C# code for your file will be generated in the right pane of the tool. Add this to your C# solution and generate files with that desired look.

As a bonus, this method works for any Word and PowerPoint files. As the C# developer, you will then make changes to the code to fit your needs.

I have developed a simple WPF app on github [1] which will run on Windows for this purpose. There is a placeholder class called GeneratedClass where you can paste the generated code. If you go back one version of the file, it will generate an excel file like this:

enter image description here


(1) I haven't tried this Open XML SDK solution yet but Wow, I will definitely check it out. I've worked with tools like this for many years and didn't know about this one. I've published my own simple FOSS for converting files to XLSX with .NET: - TonyG
[+8] [2009-11-10 05:02:18] user35711

Some useful Excel automation in C# , u can find from the following link.


[+8] [2011-04-12 07:04:36] Bonnie Cornell

Look at samples how to create Excel files.

There are examples in C# and VB.NET

It manages XSL XSLX and CSV Excel files. [1]


[+7] [2008-09-30 00:53:38] Nick

The Java open source solution is Apache POI [1]. Maybe there is a way to setup interop here, but I don't know enough about Java to answer that.

When I explored this problem I ended up using the Interop assemblies.


[+7] [2008-11-04 20:15:11] Stefan Koelle

Have you ever tried sylk?

We used to generate excelsheets in classic asp as sylk and right now we're searching for an excelgenerater too.

The advantages for sylk are, you can format the cells.

[+6] [2010-07-09 19:21:26] ScaleOvenStove

You can just write it out to XML using the Excel XML format and name it with .XLS extension and it will open with excel. You can control all the formatting (bold, widths, etc) in your XML file heading.

There is an example XML from Wikipedia [1].


[+5] [2009-10-22 15:21:25] community_owned

I also vote for GemBox.Spreadsheet [1].

Very fast and easy to use, with tons of examples on their site.

Took my reporting tasks on a whole new level of execution speed.


[+5] [2017-12-07 20:40:09] AlexDev

One really easy option which is often overlooked is to create a .rdlc report using Microsoft Reporting [1] and export it to excel format. You can design it in visual studio and generate the file using:

localReport.Render("EXCELOPENXML", null, ((name, ext, encoding, mimeType, willSeek) => stream = new FileStream(name, FileMode.CreateNew)), out warnings);

You can also export it do .doc or .pdf, using "WORDOPENXML" and "PDF" respectively, and it's supported on many different platforms such as ASP.NET and SSRS.

It's much easier to make changes in a visual designer where you can see the results, and trust me, once you start grouping data, formatting group headers, adding new sections, you don't want to mess with dozens of XML nodes.


[+3] [2011-02-09 10:39:33] Craig Mc <= why not just use the built in power of windows, just install office on the server, any application that you install can be automated.

So much easier just use the native methods.

If it installed you can use it, this is the most awesome and under used feature in windows it was Dubbed COM back in the good old days, and it saves you tons of time and pain.

Or even easier just use the ref lib MS supplies -

Why is the second way easier? Isn't it the same (adding the native object library to your project)? Do you need to have Excel installed to get this object library working? - Slauma
(7) Microsoft does not recommend or support Office Automation from non-interactive applications such as ASP.NET. See - TrueWill
Excel is quite unreliable & slow when it comes to Automation. - Leslie Godwin
[+2] [2019-12-05 21:14:52] Michael Mainer

How to create an Excel (.xslx) file using C# on OneDrive without installing Microsoft Office

The Microsoft Graph API [1] provides File and Excel APIs for creating and modifying Excel files stored in OneDrive for both enterprise and consumer accounts. The Microsoft.Graph [2] NuGet package provides many interfaces for working with the File and Excel APIs.

  Name = "myExcelFile.xslx",
  File = new Microsoft.Graph.File()

// Create an empty file in the user's OneDrive.
var excelWorkbookDriveItem = await graphClient.Me.Drive.Root.Children.Request().AddAsync(excelWorkbook);

// Add the contents of a template Excel file.
DriveItem excelDriveItem;
using (Stream ms = ResourceHelper.GetResourceAsStream(ResourceHelper.ExcelTestResource))
    //Upload content to the file. ExcelTestResource is an empty template Excel file.
    excelDriveItem = await graphClient.Me.Drive.Items[excelWorkbookDriveItem.Id].Content.Request().PutAsync<DriveItem>(ms);

At this point, you now have an Excel file created in the user (enterprise or consumer) or group's OneDrive. You can now use the Excel APIs [3] to make changes to the Excel file without using Excel and without needing to understand the Excel XML format.


[+2] [2019-12-20 19:02:46] Roman.Pavelko

You can try my SwiftExcel [1] library. This library writes directly to the file, so it is very efficient. For example you can write 100k rows in few seconds without any memory usage.

Here is a simple example of usage:

using (var ew = new ExcelWriter("C:\\temp\\test.xlsx"))
    for (var row = 1; row <= 10; row++)
        for (var col = 1; col <= 5; col++)
            ew.Write($"row:{row}-col:{col}", col, row);

[+1] [2017-04-05 09:00:59] Gayan Chinthaka Dharmarathna

If you make data table or datagridview from the code you can save all data using this simple method.this method not recomended but its working 100%, even you are not install MS Excel in your computer.

  SaveFileDialog saveFileDialog1 = new SaveFileDialog();
  saveFileDialog1.Filter = "Excel Documents (*.xls)|*.xls";
  saveFileDialog1.FileName = "Employee Details.xls";
  if (saveFileDialog1.ShowDialog() == DialogResult.OK)
  string fname = saveFileDialog1.FileName;
  StreamWriter wr = new StreamWriter(fname);
  for (int i = 0; i <DataTable.Columns.Count; i++)
  wr.Write(DataTable.Columns[i].ToString().ToUpper() + "\t");

  //write rows to excel file
  for (int i = 0; i < (DataTable.Rows.Count); i++)
  for (int j = 0; j < DataTable.Columns.Count; j++)
  if (DataTable.Rows[i][j] != null)
  wr.Write(Convert.ToString(getallData.Rows[i][j]) + "\t");
   //go to next line
   //close file
   catch (Exception)
    MessageBox.Show("Error Create Excel Sheet!");

[+1] [2017-09-27 15:18:35] Vladimir Venegas

Some time ago, I created a DLL on top of NPOI. It's very simple to use it:

IList<DummyPerson> dummyPeople = new List<DummyPerson>();
//Add data to dummyPeople...
IExportEngine engine = new ExcelExportEngine();
MemoryStream memory = engine.Export();

You could read more about it on here [1].

By the way, is 100% open source. Feel free to use, edit and share ;)


[+1] [2018-11-05 07:46:39] Vijay Dodamani

To save xls into xlsx format, we just need to call SaveAs method from Microsoft.Office.Interop.Excel library. This method will take around 16 parameters and one of them is file format as well.

Microsoft document: Here SaveAs Method Arguments [1]

The object we need to pass is like

wb.SaveAs(filename, 51, System.Reflection.Missing.Value,
System.Reflection.Missing.Value, false, false, 1,1, true, 
System.Reflection.Missing.Value, System.Reflection.Missing.Value, System.Reflection.Missing.Value)

Here, 51 is is enumeration value for XLSX

For SaveAs in different file formats you can refer the xlFileFormat [2]


[0] [2020-06-30 11:49:43] Miguel Silva

You can install OpenXml nuget package on Visual Studio. Here is a bit of code to export a data table to an excel file:

Imports DocumentFormat.OpenXml
Imports DocumentFormat.OpenXml.Packaging
Imports DocumentFormat.OpenXml.Spreadsheet

Public Class ExportExcelClass
    Public Sub New()

    End Sub

    Public Sub ExportDataTable(ByVal table As DataTable, ByVal exportFile As String)
        ' Create a spreadsheet document by supplying the filepath.
        ' By default, AutoSave = true, Editable = true, and Type = xlsx.
        Dim spreadsheetDocument As SpreadsheetDocument = spreadsheetDocument.Create(exportFile, SpreadsheetDocumentType.Workbook)

        ' Add a WorkbookPart to the document.
        Dim workbook As WorkbookPart = spreadsheetDocument.AddWorkbookPart
        workbook.Workbook = New Workbook

        ' Add a WorksheetPart to the WorkbookPart.
        Dim Worksheet As WorksheetPart = workbook.AddNewPart(Of WorksheetPart)()
        Worksheet.Worksheet = New Worksheet(New SheetData())

        ' Add Sheets to the Workbook.
        Dim sheets As Sheets = spreadsheetDocument.WorkbookPart.Workbook.AppendChild(Of Sheets)(New Sheets())

        Dim data As SheetData = Worksheet.Worksheet.GetFirstChild(Of SheetData)()
        Dim Header As Row = New Row()
        Header.RowIndex = CType(1, UInt32)

        For Each column As DataColumn In table.Columns
            Dim headerCell As Cell = createTextCell(table.Columns.IndexOf(column) + 1, 1, column.ColumnName)


        Dim contentRow As DataRow
        For i As Integer = 0 To table.Rows.Count - 1
            contentRow = table.Rows(i)
            data.AppendChild(createContentRow(contentRow, i + 2))

    End Sub

    Private Function createTextCell(ByVal columnIndex As Integer, ByVal rowIndex As Integer, ByVal cellValue As Object) As Cell
        Dim cell As Cell = New Cell()
        cell.DataType = CellValues.InlineString

        cell.CellReference = getColumnName(columnIndex) + rowIndex.ToString

        Dim inlineString As InlineString = New InlineString()
        Dim t As Text = New Text()
        t.Text = cellValue.ToString()
        Return cell
    End Function

    Private Function createContentRow(ByVal dataRow As DataRow, ByVal rowIndex As Integer) As Row
        Dim row As Row = New Row With {
            .rowIndex = CType(rowIndex, UInt32)

        For i As Integer = 0 To dataRow.Table.Columns.Count - 1
            Dim dataCell As Cell = createTextCell(i + 1, rowIndex, dataRow(i))

        Return row
    End Function

    Private Function getColumnName(ByVal columnIndex As Integer) As String
        Dim dividend As Integer = columnIndex
        Dim columnName As String = String.Empty
        Dim modifier As Integer

        While dividend > 0
            modifier = (dividend - 1) Mod 26
            columnName = Convert.ToChar(65 + modifier).ToString() & columnName
            dividend = CInt(((dividend - modifier) / 26))
        End While

        Return columnName
    End Function
End Class

[-1] [2019-01-04 05:17:40] Shubham

check this out no need for third party libraries you can simply export datatable data to excel file using this

var dt = "your code for getting data into datatable";
            Response.AddHeader("content-disposition", string.Format("attachment;filename={0}.xls", DateTime.Now.ToString("yyyy-MM-dd")));
            Response.ContentType = "application/";
            string tab = "";
            foreach (DataColumn dataColumn in dt.Columns)
                Response.Write(tab + dataColumn.ColumnName);
                tab = "\t";
            int i;
            foreach (DataRow dataRow in dt.Rows)
                tab = "";
                for (i = 0; i < dt.Columns.Count; i++)
                    Response.Write(tab + dataRow[i].ToString());
                    tab = "\t";

(4) That generates a tab-separated file and saves it with an .XLS extension so that it gets opened by Excel. It's not a real Excel file, and you can't include formatting etc. There are similar answers here which try the same trick with HTML and the wrong extension. - Rup
[-7] [2014-12-20 06:37:43] saurabh27

I am using following code for create excel 2007 file which create the file and write in that file but when i open the file but it give me error that exel cannot open the file bcz file might be coruupted or extension of the file is not compatible. but if i used .xls for file it work fines

for (int i = 0; i < TotalFile; i++)
    if (innerloop == SplitSize)
        for (int j = 0; j < SplitSize; j++)
            string strContact = DSt.Tables[0].Rows[i * SplitSize + j][0].ToString();
        string strExcel = strFileName + "_" + i.ToString() + ".xlsx";
                         File.WriteAllLines(strExcel, Contact.ToArray());

also refer link

(2) That all relies on your Contact class, and you haven't told us what that is. If it works for xls then chances are you're actually writing out HTML which isn't a real Excel file. And your link is using interop, which as mentioned above shouldn't be used server-side and can be slow filling large tables. - Rup
(1) Contact is linkedlist not a class.declare a linkledist and used it because i haven't know the size of data so i used linkedlist. - saurabh27
(1) Oh, so you're producing a plain text file with one item per line? So Excel is treating it as a CSV without the commas? - Rup