---
title: "Merge PDF C# .NET: Combine and merge multiple files to PDF | Nutrient .NET SDK"
canonical_url: "https://www.nutrient.io/guides/dotnet/conversion/merge-to-pdf/"
md_url: "https://www.nutrient.io/guides/dotnet/conversion/merge-to-pdf.md"
last_updated: "2026-05-15T19:10:04.980Z"
description: "Learn how to merge and combine multiple files into a single PDF in C#. Follow our guide for seamless PDF merging in your .NET applications."
---

# Merge and combine multiple files into a PDF in C#

This guide explains how to merge multiple PDF files into a single PDF file. It also explains how to combine files of different types into a single PDF file. The procedure explained in this guide works for all [supported file types](https://www.nutrient.io/guides/dotnet/about/file-type-support.md).

## Merging multiple PDF files into a single PDF file

To create a single PDF file from multiple PDF files, follow these steps:

1. Create a `GdPictureDocumentConverter` object.

2. Add the file paths of the source PDF documents to a list.

3. Save the output in a new PDF document with the `CombineToPDF` method. It takes the following parameters:
   - The list of source file paths.
   - The path to the output PDF file.
   - A member of the `PdfConformance` enumeration that specifies the conformance level of the output PDF file. For example, use `PDF` to create a common PDF document.

The example below creates a single PDF document from multiple PDF files:

### C#

```csharp

using GdPictureDocumentConverter gdpictureDocumentConverter = new GdPictureDocumentConverter();
// Add the source PDF documents to a list.
IEnumerable<string> sourceFiles = new List<string>(new string[] {
    @"C:\temp\source1.pdf",
    @"C:\temp\source2.pdf",
    @"C:\temp\source3.pdf",
    @"C:\temp\source4.pdf"
});
// Save the output in a new PDF document.
gdpictureDocumentConverter.CombineToPDF(sourceFiles, @"C:\temp\output.pdf", PdfConformance.PDF);

```

### VB.NET

```vb

Using gdpictureDocumentConverter As GdPictureDocumentConverter = New GdPictureDocumentConverter()
    ' Add the source PDF documents to a list.
    Dim sourceFiles As IEnumerable(Of String) = New List(Of String)(New String() {"C:\temp\source1.pdf", "C:\temp\source2.pdf", "C:\temp\source3.pdf", "C:\temp\source4.pdf"})
    ' Save the output in a new PDF document.
    gdpictureDocumentConverter.CombineToPDF(sourceFiles, "C:\temp\output.pdf", PdfConformance.PDF)
End Using

```

#### Used Methods

- [`CombineToPDF`](/api/gdpicture/GdPicture.NET.14.API~GdPicture14.GdPictureDocumentConverter~CombineToPDF.html)

- [`PdfConformance`](/api/gdpicture/GdPicture.NET.14.API~GdPicture14.PdfConformance.html)

#### Related Topics

- [Load a File](/guides/dotnet/load-a-file.md)

- [Save a File](/guides/dotnet/save-a-file.md)

## Combining files of different types into a single PDF file

To combine files of different types into a single PDF file, follow these steps:

1. Create a `GdPictureDocumentConverter` object.

2. Add the file paths of the source files to a list.

3. Save the output in a new PDF document with the `CombineToPDF` method. It takes the following parameters:
   - The list of source file paths.
   - The path to the output PDF file.
   - A member of the `PdfConformance` enumeration that specifies the conformance level of the output PDF file. For example, use `PDF` to create a common PDF document.

The example below creates a single PDF document from files of different types:

### C#

```csharp

using GdPictureDocumentConverter gdpictureDocumentConverter = new GdPictureDocumentConverter();
// Add the source files to a list.
IEnumerable<string> sourceFiles = new List<string>(new string[] {
    @"C:\temp\source.png",
    @"C:\temp\source.pdf",
    @"C:\temp\source.tiff",
    @"C:\temp\source.txt"
});
// Save the output in a new PDF document.
gdpictureDocumentConverter.CombineToPDF(sourceFiles, @"C:\temp\output.pdf", PdfConformance.PDF);

```

### VB.NET

```vb

Using gdpictureDocumentConverter As GdPictureDocumentConverter = New GdPictureDocumentConverter()
    ' Add the source files to a list.
    Dim sourceFiles As IEnumerable(Of String) = New List(Of String)(New String() {"C:\temp\source.png", "C:\temp\source.pdf", "C:\temp\source.tiff", "C:\temp\source.txt"})
    ' Save the output in a new PDF document.
    gdpictureDocumentConverter.CombineToPDF(sourceFiles, "C:\temp\output.pdf", PdfConformance.PDF)
End Using

```

#### Used Methods

- [`CombineToPDF`](/api/gdpicture/GdPicture.NET.14.API~GdPicture14.GdPictureDocumentConverter~CombineToPDF.html)

- [`PdfConformance`](/api/gdpicture/GdPicture.NET.14.API~GdPicture14.PdfConformance.html)

#### Related Topics

- [Load a File](/guides/dotnet/load-a-file.md)

- [Save a File](/guides/dotnet/save-a-file.md)
---

## Related pages

- [Convert any image to PDF in C#](/guides/dotnet/conversion/any-image-to-pdf.md)
- [Convert bitmap (BMP) to PDF in C#](/guides/dotnet/conversion/bmp-to-pdf.md)
- [Convert DWG or DXF to PDF in C#](/guides/dotnet/conversion/cad-to-pdf.md)
- [Convert to MS Office from any file in C#](/guides/dotnet/conversion/any-file-to-office.md)
- [Convert emails (MSG/EML) to PDF in C#](/guides/dotnet/conversion/email-to-pdf.md)
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- [Embed a font in a Word document](/guides/dotnet/conversion/embed-font-in-word-document.md)
- [Convert Excel to PDF in C#](/guides/dotnet/conversion/excel-to-pdf.md)
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- [Convert PDF to Excel in C#](/guides/dotnet/conversion/pdf-to-excel.md)
- [Convert JPG to PDF in C#](/guides/dotnet/conversion/jpg-to-pdf.md)
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- [Convert PDF to JPG in C#](/guides/dotnet/conversion/pdf-to-jpg.md)
- [Converting a document from PDF to Markdown format](/guides/dotnet/conversion/pdf-to-markdown.md)
- [Convert PDF to PDF/A](/guides/dotnet/conversion/pdf-to-pdfa.md)
- [Convert PDF to PNG in C#](/guides/dotnet/conversion/pdf-to-png.md)
- [Convert PDF to other images in C#](/guides/dotnet/conversion/pdf-to-other-image.md)
- [Convert PDF to PDF/UA](/guides/dotnet/conversion/pdf-to-pdf-ua.md)
- [Convert PDF to PowerPoint in C#](/guides/dotnet/conversion/pdf-to-powerpoint.md)
- [Convert PDF to SVG in C#](/guides/dotnet/conversion/pdf-to-svg.md)
- [Convert PDF to TIFF in C#](/guides/dotnet/conversion/pdf-to-tiff.md)
- [Convert PDF to Word in C#](/guides/dotnet/conversion/pdf-to-word.md)
- [Convert PNG to PDF in C#](/guides/dotnet/conversion/png-to-pdf.md)
- [Convert RTF to PDF in C#](/guides/dotnet/conversion/rtf-to-pdf.md)
- [Convert PowerPoint to PDF in C#](/guides/dotnet/conversion/powerpoint-to-pdf.md)
- [Convert SVG to PDF in C#](/guides/dotnet/conversion/svg-to-pdf.md)
- [Convert text to PDF in C#](/guides/dotnet/conversion/text-to-pdf.md)
- [Convert RTF to Word in C#](/guides/dotnet/conversion/rtf-to-docx.md)
- [Convert to Word, Excel, or PowerPoint in C#](/guides/dotnet/conversion/to-office.md)
- [Convert TIFF to PDF in C#](/guides/dotnet/conversion/tiff-to-pdf.md)
- [Convert Word to PDF in C#](/guides/dotnet/conversion/word-to-pdf.md)