What It Does
One .NET library. Open a document, change it, save it, and draw its pages.
Open, Edit, and Save
Opens .docx, .xlsx, .xlsm, .pptx, .csv, and .tsv files, saves them in place or as a new file, and creates blank documents, workbooks, and decks.
Page Images and PDF
Renders any page to a PNG image at 24 to 600 dpi, and exports a whole document to PDF.
Word Documents
Reads a document’s text, replaces text throughout it, and compares two documents into a third that shows the differences as tracked changes.
Workbooks
Lists the sheets, reads and sets what a cell holds, and reads the value a formula calculates, as the cell shows it.
Made for .NET
What you would otherwise have to check for yourself before putting a document engine in your Windows software.
- One package. Each release on GitHub attaches ComOfficeKit’s .nupkg: add its folder as a package source and reference ComOfficeKit from a .NET 8 or later project. The engine travels with your app, about 76 MB, and nothing is installed on the machine.
- Typed errors. A file the engine cannot read throws a ComOfficeKitException that says which kind of failure it was.
- A licence in one line. Call License.Activate with your key, or License.ActivateFromFile. A licence can be bound to your app, and the activation is kept for the Windows user or only in memory.
Platforms
Windows 11 on x64, with .NET 8 or later. It does not run on .NET Framework.
Formats
.docx, .xlsx, .xlsm, .pptx, .csv, and .tsv in; the same formats, PNG page images, and PDF out. Older .doc, .xls, and .ppt files are not opened.
Documentation
Guides to getting started, licensing, rendering and PDF, spreadsheets, the document model, errors and threading, deployment, and limits, with four sample apps, in its GitHub repository. The package’s XML documentation appears in IntelliSense. Read the API reference online.
More Features on the Way
Some advanced features are not in the SDK yet. We are adding them release by release; tell us what your project needs.
Frequently Asked Questions
How do I get ComOfficeKit for Windows?
Download it from GitHub: each release attaches the package, and its README publishes a free evaluation key, valid for about 60 days. For a licence, tell our sales team about your project on the contact form, or write to support@comofficekit.com.
Which versions of Windows and .NET does it support?
Windows 11 on x64, with .NET 8 or later. It does not run on .NET Framework.
Can I run it on Windows Server?
Not yet. Windows Server and Linux are in development.
Can it open PDF files?
No. ComOfficeKit works with .docx, .xlsx, .xlsm, .pptx, .csv, and .tsv files and exports them to PDF. It does not open or edit PDF documents.
Is the API stable?
Yes. It keeps to semantic versioning: a 1.x version adds to it, and nothing your code compiles against is removed or changed before 2.0. Since 1.1.0 that includes the document model, ComOfficeKit.Model, which reads and edits paragraphs, cells, and slides as records.
Ask About ComOfficeKit for Windows
Tell us what you are building, and our sales team will get back to you. You can also write to support@comofficekit.com.