Read-only mode

To prevent other users from modifying your Excel files, set them to open in read-only mode.

Protect specific sheets

One or more worksheets in an Excel file can be protected with passwords.

Protect workbooks

Using a password, you can protect an entire Excel workbook's structure, including the sheet titles, order, and other details.


Excel files can be encrypted and decrypted using a password to conceal worksheet data and workbook structure.

Mark as final

To stop further editing, typing, or reviewing of an Excel document, mark the document as final.

A feature-rich and high-performance Excel library that lets you integrate powerful Excel functionality into any.NET application. Create, read, and edit Excel documents  programmatically without Microsoft Office dependencies.

Syncfusion C# Excel Libraries