Split PDF Files in C#

Overview

The Syncfusion .NET PDF library that allows users to split a PDF file into multiple sub-documents quickly and accurately. It also allows users to split, combine, import, and append PDFs.

The split PDF feature works seamlessly on various platforms: WinForms, WPF, Blazor, .NET MAUI, WinUI, Flutter, ASP.NET MVC, ASP.NET Core, UWP, Xamarin with Windows, Linux, and MacOS.

Split PDF c#

How to split PDF files in C#

Install the Syncfusion.Pdf.Net.Core NuGet package in your project.
Create FileStream objects to represent input PDF files.
Create a PdfLoadedDocument object by passing the FileStream object.
Create a new PDF document using the PdfDocument class.
Use the ImportPage method of the PdfDocumentBase class to split a PDF document into multiple files.
Save the PdfDocument object to the FileStream object.

Here is an example of how to split PDF files in C# using the Syncfusion .NET PDF library. You can split a PDF file into a single page or multiple page PDF document with just a few lines of code.

c#
//Create the FileStream object
using (FileStream inputFileStream = new FileStream("Input.pdf", FileMode.Open, FileAccess.Read))
//Load the PDF document from stream
using (PdfLoadedDocument loadedDocument = new PdfLoadedDocument(inputFileStream)) 
{
    //Iterate over the pages 
    for (int pageIndex = 0; pageIndex < loadedDocument.PageCount; pageIndex++) 
    {
        //Create a new PdfDocument object
        using (PdfDocument outputDocument = new PdfDocument())   
        {
            //Import the page from the loadedDocument to the outputDocument
            outputDocument.ImportPage(loadedDocument, pageIndex); 
            //Save the document into a filestream object
            using (FileStream outputFileStream = new FileStream("Output" + pageIndex + ".pdf", FileMode.Create, FileAccess.Write))
            {
                outputDocument.Save(outputFileStream);
            }
        }
    }
}

PDF split options

Split a range of pages into a separate PDF document

A range of pages can be split into a separate PDF document.

c#
//Load the existing PDF file.
using (PdfLoadedDocument loadDocument = new PdfLoadedDocument(new FileStream("Input.pdf", FileMode.Open)))
{
    //Subscribe to the document split event.
    loadDocument.DocumentSplitEvent += LoadDocument_DocumentSplitEvent;
    void LoadDocument_DocumentSplitEvent(object sender, PdfDocumentSplitEventArgs args)
    {
        //Save the resulting document.
        using (FileStream outputStream = new FileStream(Guid.NewGuid().ToString() + ".pdf", FileMode.CreateNew))
        {
            args.PdfDocumentData.CopyTo(outputStream);
        }
    }
    //Spit the document by ranges.
    loadDocument.SplitByRanges(new int[,] { { 0, 5 }, { 5, 10 } });
}

Import or delete certain pages from a PDF file

Users can get specific pages or delete certain pages from a PDF document.

c#
//Create the FileStream object
using (FileStream inputFilestream = new FileStream("Input.pdf", FileMode.Open, FileAccess.Read))
//Load the PDF document from stream
using (PdfLoadedDocument loadedDocument = new PdfLoadedDocument(inputFilestream)) 
{
    //Creates a new PDF document
    using (PdfDocument outputDocument = new PdfDocument()) 
    {
        //Remove the first page in the PDF document  
        loadedDocument.Pages.RemoveAt(0);
        //Import certain pages to the new PDF document 
        outputDocument.ImportPage(loadedDocument, 0); 
        //Save the document into a filestream object 
        using (FileStream outputFileStream = new FileStream("Output.pdf", FileMode.Create, FileAccess.Write))
        {
            outputDocument.Save(outputFileStream);
        }
    }
}

Split a document based on bookmarks

Split a PDF document based on bookmarks.

c#
//Create the FileStream object 
using (FileStream fileStream = new FileStream("Input.pdf", FileMode.Open, FileAccess.Read))
//Load the PDF document from stream
using (PdfLoadedDocument loadedDocument = new PdfLoadedDocument(fileStream))  
{
    //Create bookmark object
    PdfBookmarkBase bookmarks = loadedDocument.Bookmarks;
    //Load the PDF document from stream
    foreach (PdfBookmark bookmark in bookmarks) 
    {
        if (bookmark.Destination != null)
        {
            if (bookmark.Destination.Page != null)
            {
                int endIndex = bookmark.Destination.PageIndex;
                //Create a new PDF document
                using (PdfDocument document = new PdfDocument()) 
                {
                    foreach (PdfLoadedBookmark childBookmark in bookmark)
                    {
                        endIndex = childBookmark.Destination.PageIndex;
                    }
                    //Import the pages to the new PDF document
                    document.ImportPageRange(loadedDocument, bookmark.Destination.PageIndex, endIndex);
                    //Save the PDF file with the bookamark title's name.
                    using (var outputFileStream = new FileStream(bookmark.Title + ".pdf", FileMode.Create, FileAccess.Write))
                    {
                        document.Save(outputFileStream);
                    }
                }
            }
        }
    }
}