Split Word Documents Using the Syncfusion .NET Word Library

The Syncfusion^® .NET Word Library offers powerful APIs to programmatically split large Word documents into multiple smaller ones with ease. Achieve document segmentation in just a few lines of code, all without relying on Microsoft Word or interop dependencies.

DocIO supports splitting Word documents by:

Section
Heading
Bookmark
Placeholder

This allows developers to extract specific portions of a document or generate multiple documents efficiently based on the required splitting logic.

Watch this video to learn how to split a Word document using the Syncfusion .NET Word Library.

Watch the video

Split Word document using C#

Learn how to split Word documents programmatically using C# with the Syncfusion .NET Word Library. This guide demonstrates splitting documents by section and heading to create multiple smaller documents from a single large document.

Step 1: Create a new project

Start by creating a new C# Console Application project.

Step 2: Install the NuGet package

Add the Syncfusion.DocIO.Net.Core package to your project from NuGet.org.

Step 3: Add required namespaces to split Word document

Add the following namespaces to your Program.cs file:

c#
using System.IO;
using Syncfusion.DocIO;
using Syncfusion.DocIO.DLS;

Step 4: Split Word document by section

Split each section of a Word document into separate Word documents.

Run

c#
using (FileStream inputStream = new FileStream(Path.GetFullPath(@"Data/Template.docx"), FileMode.Open, FileAccess.Read, FileShare.ReadWrite))
{
    //Load the template document as stream
    using (WordDocument document = new WordDocument(inputStream, FormatType.Docx))
    {
        //Iterate each section from Word document
        for (int i = 0; i < document.Sections.Count; i++)
        {
            //Create new Word document
            using (WordDocument newDocument = new WordDocument())
            {
                //Add cloned section into new Word document
                newDocument.Sections.Add(document.Sections[i].Clone());
                //Save the Word document to  MemoryStream
                using (FileStream outputStream = new FileStream(Path.GetFullPath(@"Output/Section") + i + ".docx", FileMode.OpenOrCreate, FileAccess.ReadWrite))
                {
                    newDocument.Save(outputStream, FormatType.Docx);
                }
            }
        }
    }
}

Step 5: Split Word document by headings

Split each heading and its associated content into separate Word documents.

Run

c#
using (FileStream inputStream = new FileStream(Path.GetFullPath(@"Data/Template.docx"), FileMode.Open, FileAccess.Read))
  {
      //Load the template document as stream
      using (WordDocument document = new WordDocument(inputStream, FormatType.Docx))
      {
          WordDocument newDocument = null;
          WSection newSection = null;
          int headingIndex = 0;
          //Iterate each section in the Word document
          foreach (WSection section in document.Sections)
          {
              // Clone the section and add into new document
              if (newDocument != null)
                  newSection = AddSection(newDocument, section);
              //Iterate each child entity in the Word document
              foreach (TextBodyItem item in section.Body.ChildEntities)
              {
                  //If item is paragraph, then check for heading style and split
                  //else, add the item into new document
                  if (item is WParagraph)
                  {
                      WParagraph paragraph = item as WParagraph;
                      //If paragraph has Heading 1 style, then save the traversed content as separate document
                      //And create new document for new heading content
                      if (paragraph.StyleName == "Heading 1")
                      {
                          if (newDocument != null)
                          {
                              //Save the Word document
                              string fileName = Path.GetFullPath(@"Output/Document") + (headingIndex + 1) + ".docx";
                              SaveWordDocument(newDocument, fileName);
                              headingIndex++;
                          }
                          //Create new document for new heading content
                          newDocument = new WordDocument();
                          newSection = AddSection(newDocument, section);
                          AddEntity(newSection, paragraph);
                      }
                      else if (newDocument != null)
                          AddEntity(newSection, paragraph);
                  }
                  else
                      AddEntity(newSection, item);
              }
          }
          //Save the remaining content as separate document
          if (newDocument != null)
          {
              //Save the Word document
              string fileName = Path.GetFullPath(@"Output/Document") + (headingIndex + 1) + ".docx";
              SaveWordDocument(newDocument, fileName);
          }
      }
  }

Add the helper methods to split a Word document by headings

c#
/// <summary>
/// Add new section to Word document
/// </summary>
private static WSection AddSection(WordDocument newDocument, WSection section)
{
    //Create new session based on original document
    WSection newSection = section.Clone();
    newSection.Body.ChildEntities.Clear();
    //Remove the first page header.
    newSection.HeadersFooters.FirstPageHeader.ChildEntities.Clear();
    //Remove the first page footer.
    newSection.HeadersFooters.FirstPageFooter.ChildEntities.Clear();
    //Remove the odd footer.
    newSection.HeadersFooters.OddFooter.ChildEntities.Clear();
    //Remove the odd header.
    newSection.HeadersFooters.OddHeader.ChildEntities.Clear();
    //Remove the even header.
    newSection.HeadersFooters.EvenHeader.ChildEntities.Clear();
    //Remove the even footer.
    newSection.HeadersFooters.EvenFooter.ChildEntities.Clear();
    //Add cloned section into new document
    newDocument.Sections.Add(newSection);
    return newSection;
}
/// <summary>
/// Add Entity to new section
/// </summary>
private static void AddEntity(WSection newSection, Entity entity)
{
    //Add cloned item into the newly created section
    newSection.Body.ChildEntities.Add(entity.Clone());
}
/// <summary>
/// Save Word document
/// </summary>
private static void SaveWordDocument(WordDocument newDocument, string fileName)
{
    using (FileStream outputStream = new FileStream(Path.GetFullPath(fileName), FileMode.OpenOrCreate, FileAccess.ReadWrite))
    {
        //Save file stream as Word document
        newDocument.Save(outputStream, FormatType.Docx);
        //Closes the document
        newDocument.Close();
        newDocument = null;
    }
}

Step 6: Split Word document by bookmark

Split the content of each bookmark into separate Word documents.

Run

c#
using (FileStream fileStreamPath = new FileStream(Path.GetFullPath(@"Data/Template.docx"), FileMode.Open, FileAccess.Read, FileShare.ReadWrite))
{
    using (WordDocument document = new WordDocument(fileStreamPath, FormatType.Docx))
    {
        //Create the bookmark navigator instance to access the bookmark
        BookmarksNavigator bookmarksNavigator = new BookmarksNavigator(document);
        BookmarkCollection bookmarkCollection = document.Bookmarks;
        //Iterate each bookmark in Word document
        foreach (Bookmark bookmark in bookmarkCollection)
        {
            //Move the virtual cursor to the location before the end of the bookmark
            bookmarksNavigator.MoveToBookmark(bookmark.Name);
            //Get the bookmark content as WordDocumentPart
            WordDocumentPart documentPart = bookmarksNavigator.GetContent();
            //Save the WordDocumentPart as separate Word document
            using (WordDocument newDocument = documentPart.GetAsWordDocument())
            {
                //Save the Word document to file stream
                using (FileStream outputFileStream = new FileStream(Path.GetFullPath(@"Output/" + bookmark.Name + ".docx"), FileMode.Create, FileAccess.ReadWrite))
                {
                    newDocument.Save(outputFileStream, FormatType.Docx);
                }
            }
        }
    }

}

Step 7: Split Word document by placeholder

Split a Word document by finding placeholder text and extracting content between placeholders into separate documents.

Run

c#
using (FileStream fileStreamPath = new FileStream(Path.GetFullPath(@"Data/Template.docx"), FileMode.Open, FileAccess.Read, FileShare.ReadWrite))
 {
     using (WordDocument document = new WordDocument(fileStreamPath, FormatType.Docx))
     {

         //Find all the placeholder text in the Word document
         TextSelection[] textSelections = document.FindAll(new Regex("<<(.*)>>"));
         if (textSelections != null)
         {
             #region Insert bookmarks at placeholders
             //Unique ID for each bookmark
             int bkmkId = 1;
             //Collection to hold the inserted bookmarks
             List<string> bookmarks = new List<string>();
             //Iterate each text selection
             for (int i = 0; i < textSelections.Length; i++)
             {
                 #region Insert bookmark start before the placeholder
                 //Get the placeholder as WTextRange
                 WTextRange textRange = textSelections[i].GetAsOneRange();
                 //Get the index of the placeholder text
                 WParagraph startParagraph = textRange.OwnerParagraph;
                 int index = startParagraph.ChildEntities.IndexOf(textRange);
                 string bookmarkName = "Bookmark_" + bkmkId;
                 //Add new bookmark to bookmarks collection
                 bookmarks.Add(bookmarkName);
                 //Create bookmark start
                 BookmarkStart bkmkStart = new BookmarkStart(document, bookmarkName);
                 //Insert the bookmark start before the start placeholder
                 startParagraph.ChildEntities.Insert(index, bkmkStart);
                 //Remove the placeholder text
                 textRange.Text = string.Empty;
                 #endregion

                 #region Insert bookmark end after the placeholder
                 i++;
                 //Get the placeholder as WTextRange
                 textRange = textSelections[i].GetAsOneRange();
                 //Get the index of the placeholder text
                 WParagraph endParagraph = textRange.OwnerParagraph;
                 index = endParagraph.ChildEntities.IndexOf(textRange);
                 //Create bookmark end
                 BookmarkEnd bkmkEnd = new BookmarkEnd(document, bookmarkName);
                 //Insert the bookmark end after the end placeholder
                 endParagraph.ChildEntities.Insert(index + 1, bkmkEnd);
                 bkmkId++;
                 //Remove the placeholder text
                 textRange.Text = string.Empty;
                 #endregion

             }
             #endregion
             #region Split bookmark content into separate documents 
             BookmarksNavigator bookmarksNavigator = new BookmarksNavigator(document);
             int fileIndex = 1;
             foreach (string bookmark in bookmarks)
             {
                 //Move the virtual cursor to the location before the end of the bookmark
                 bookmarksNavigator.MoveToBookmark(bookmark);
                 //Get the bookmark content as WordDocumentPart
                 WordDocumentPart wordDocumentPart = bookmarksNavigator.GetContent();
                 //Save the WordDocumentPart as separate Word document
                 using (WordDocument newDocument = wordDocumentPart.GetAsWordDocument())
                 {
                     //Save the Word document to file stream
                     using (FileStream outputFileStream = new FileStream(Path.GetFullPath(@"Output/Placeholder_" + fileIndex + ".docx"), FileMode.Create, FileAccess.ReadWrite))
                     {
                         newDocument.Save(outputFileStream, FormatType.Docx);
                     }
                 }
                 fileIndex++;
             }
             #endregion
         }
     }
 }