# ClosedXML
**Repository Path**: binGe8614/ClosedXML
## Basic Information
- **Project Name**: ClosedXML
- **Description**: ClosedXML is a .NET library for reading, manipulating and writing Excel 2007+ (.xlsx, .xlsm) files. It aims to provide an intuitive and user-friendly interface to dealing with the underlying OpenXML API.
- **Primary Language**: Unknown
- **License**: MIT
- **Default Branch**: develop
- **Homepage**: None
- **GVP Project**: No
## Statistics
- **Stars**: 0
- **Forks**: 1
- **Created**: 2025-11-19
- **Last Updated**: 2025-11-19
## Categories & Tags
**Categories**: Uncategorized
**Tags**: None
## README
[](https://github.com/ClosedXML/ClosedXML/releases/latest) [](https://www.nuget.org/packages/ClosedXML/) [](#) [](#) [](https://ci.appveyor.com/project/ClosedXML/ClosedXML/branch/develop/artifacts)
[](https://www.codetriage.com/closedxml/closedxml)
[💾 Download unstable CI build](https://ci.appveyor.com/project/ClosedXML/ClosedXML/branch/develop/artifacts)
ClosedXML is a .NET library for reading, manipulating and writing Excel 2007+ (.xlsx, .xlsm) files. It aims to provide an intuitive and user-friendly interface to dealing with the underlying [OpenXML](https://github.com/OfficeDev/Open-XML-SDK) API.
For more information see [the documentation](https://closedxml.readthedocs.io/) or [the wiki](https://github.com/closedxml/closedxml/wiki).
### Release notes & migration guide
The public API is still not stable and it is a very good idea to **read release notes** and **migration guide** before each update.
* [Release notes for 0.100](https://github.com/ClosedXML/ClosedXML/releases/tag/0.100.0)
* [Migration guide for 0.100](https://closedxml.readthedocs.io/en/latest/migrations/migrate-to-0.100.html)
* [Release notes for 0.97](https://github.com/ClosedXML/ClosedXML/releases/tag/0.97.0)
### Performance
Performance matters mostly for large files. For small files, few ms here or there doesn't matter. The presented data are from generally develop branch (currently [0.103-beta](https://github.com/ClosedXML/ClosedXML/commit/5f7c0d9461352a6a468e5299bfef6eaf82bf37da)).
Runtime details
```
BenchmarkDotNet v0.13.8, Windows 11 (10.0.22621.2283/22H2/2022Update/SunValley2)
AMD Ryzen 5 5500U with Radeon Graphics, 1 CPU, 12 logical and 6 physical cores
.NET SDK 8.0.100-rc.1.23463.5
[Host] : .NET 7.0.11 (7.0.1123.42427), X64 RyuJIT AVX2
```
#### Save
| Description | Rows | Columns | Time/Memory to insert data | Save workbook | Total time/memory |
|------------------------------|-----------|------------------------|----------------------------|------------------------------|---|
| Mixed (text/number) workbook.
[Gist](https://gist.github.com/jahav/bdc5fe3c90f25544ca6ae1394bbe3561) | 250 000 | 15 | 1.619 sec / 117 MiB | 6.343 sec | 7.962 sec / 477 MiB |
| Text only workbook. [Gist](https://gist.github.com/jahav/257bb2ffd5ab7adfded7e669290d8151) | 1 000 000 | 10 | 6.302 sec / 402 MiB | 17.134 sec | 23.436 sec / 1880 MiB |
#### Load
| Description | Rows | Columns | Time to load data | Used memory |
|--------------------------------------------------------------------|-----------|---------|-------------------|-------------|
| Load mixed workbook (10 text/5 number columns). | 250 000 | 15 | 15.648 sec | 236 MiB |
| Text only workbook. | 1 000 000 | 10 | 49.046 sec | 801 MiB |
Load tests used files created during save test.
### Frequent answers
- If you get an exception `Unable to find font font name or fallback font fallback font name. Install missing fonts or specify a different fallback font through ‘LoadOptions.DefaultGraphicEngine = new DefaultGraphicEngine(“Fallback font name”)’`, see help page about [missing fonts](https://closedxml.readthedocs.io/en/latest/tips/missing-font.html).
- ClosedXML is not thread-safe. There is no guarantee that [parallel operations](https://github.com/ClosedXML/ClosedXML/issues/1662) will work. The underlying OpenXML library is also not thread-safe.
- If you get an exception `The type initializer for 'Gdip' threw an exception.` on Linux, you have to upgrade to 0.97+.
### Install ClosedXML via NuGet
If you want to include ClosedXML in your project, you can [install it directly from NuGet](https://www.nuget.org/packages/ClosedXML)
To install ClosedXML, run the following command in the Package Manager Console
```
PM> Install-Package ClosedXML
```
### What can you do with this?
ClosedXML allows you to create Excel files without the Excel application. The typical example is creating Excel reports on a web server.
**Example:**
```c#
using (var workbook = new XLWorkbook())
{
var worksheet = workbook.Worksheets.Add("Sample Sheet");
worksheet.Cell("A1").Value = "Hello World!";
worksheet.Cell("A2").FormulaA1 = "=MID(A1, 7, 5)";
workbook.SaveAs("HelloWorld.xlsx");
}
```
### Extensions
Be sure to check out our `ClosedXML` extension projects
- https://github.com/ClosedXML/ClosedXML.Report
- https://github.com/ClosedXML/ClosedXML.Extensions.AspNet
- https://github.com/ClosedXML/ClosedXML.Extensions.Mvc
- https://github.com/ClosedXML/ClosedXML.Extensions.WebApi
## Developer guidelines
The [OpenXML specification](https://ecma-international.org/publications-and-standards/standards/ecma-376/) is a large and complicated beast. In order for ClosedXML, the wrapper around OpenXML, to support all the features, we rely on community contributions. Before opening an issue to request a new feature, we'd like to urge you to try to implement it yourself and log a pull request.
Please read the [full developer guidelines](CONTRIBUTING.md).
## Credits
* Project originally created by Manuel de Leon
* Current maintainer: [Jan Havlíček](https://github.com/jahav)
* Former maintainer and lead developer: [Francois Botha](https://github.com/igitur)
* Master of Computing Patterns: [Aleksei Pankratev](https://github.com/Pankraty)
* Logo design by [@Tobaloidee](https://github.com/Tobaloidee)
Thanks to JetBrains for providing development tools through their [Open Source Program](https://www.jetbrains.com/community/opensource/)
[
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