MemoryStream to PDF C#

We can load, create, and export MemoryStream to PDF files in C# .NET without even touching the file system. This is possible through the MemoryStream object present inside the System.IO .NET namespace. Follow the tutorial below to find out how to export HTML to PDF in your C# project.

How to Convert PDF to MemoryStream in C#

Download the C# Library to convert PDF to MemoryStream
Load an existing PDF as PdfDocument object
Render a new PDF from a URL or an HTML string/file
Convert the PDF to a Stream using the Stream method and BinaryData property
Serve the MemoryStream to the web, including MVC and ASP.NET

Step 1

1. Install IronPDF

In this tutorial, we'll be using IronPDF's C# PDF Library to save MemoryStream files to PDF in C#. You can download it free or install to Visual Studio with NuGet.

 PM > Install-Package IronPdf

How to Tutorial

2. Load a PDF from Memory

A new instance of IronPdf.PdfDocument can be initialized in any of these .NET in-memory-objects:

A MemoryStream
A FileSteam
Binary Data as a Byte array (byte[])

Here is an example of reading a URL directly into a stream, then saving the PDF file to disk by using C#:

/**
Load PDF from Memory
anchor-load-a-pdf-from-memory
**/
    private void ReadViaMemStream()

    {

      //Conversion of the URL into PDF

      var Renderer = new IronPdf.ChromePdfRenderer();

      Uri url = new Uri("https://ironpdf.com/how-to/pdf-memory-stream/");

      MemoryStream rend = Renderer.RenderUrlAsPdf(url).Stream; //Read stream

      HttpContext.Current.Response.AddHeader("Content-Type", "application/pdf"); //Download

      HttpContext.Current.Response.AddHeader("Content-Disposition", String.Format("{0}; filename=Print.pdf; size={1}", "attachment", rend.Length.ToString()));

      // Write PDF buffer to HTTP response

      HttpContext.Current.Response.BinaryWrite(rend.ToArray());

      // Stop page processing

      HttpContext.Current.Response.End();

    }

/**
Load PDF from Memory
anchor-load-a-pdf-from-memory
**/
    private void ReadViaMemStream()

    {

      //Conversion of the URL into PDF

      var Renderer = new IronPdf.ChromePdfRenderer();

      Uri url = new Uri("https://ironpdf.com/how-to/pdf-memory-stream/");

      MemoryStream rend = Renderer.RenderUrlAsPdf(url).Stream; //Read stream

      HttpContext.Current.Response.AddHeader("Content-Type", "application/pdf"); //Download

      HttpContext.Current.Response.AddHeader("Content-Disposition", String.Format("{0}; filename=Print.pdf; size={1}", "attachment", rend.Length.ToString()));

      // Write PDF buffer to HTTP response

      HttpContext.Current.Response.BinaryWrite(rend.ToArray());

      // Stop page processing

      HttpContext.Current.Response.End();

    }

'''
'''Load PDF from Memory
'''anchor-load-a-pdf-from-memory
'''*
 Private Sub ReadViaMemStream()

  var Renderer = New IronPdf.ChromePdfRenderer()

 Uri url = New Uri("https://ironpdf.com/how-to/pdf-memory-stream/")

 MemoryStream rend = Renderer.RenderUrlAsPdf(url).Stream 'Read stream

 HttpContext.Current.Response.AddHeader("Content-Type", "application/pdf") 'Download

 HttpContext.Current.Response.AddHeader("Content-Disposition", String.Format("{0}; filename=Print.pdf; size={1}", "attachment", rend.Length.ToString()))

  HttpContext.Current.Response.BinaryWrite(rend.ToArray())

  HttpContext.Current.Response.End()

'INSTANT VB TODO TASK: The following line uses invalid syntax:
' }

VB C#

3. Save a PDF to Memory

An IronPdf.PdfDocument can be saved directly to memory in one of 2 ways:

IronPdf.PdfDocument.Stream exports the PDF as a System.IO.MemoryStream
IronPdf.PdfDocument.BinaryData exports the PDF as a Byte Array (byte[])

4. Serve a PDF to Web from Memory

To serve or export a PDF to the web, you need to send the PDF file as binary data instead of HTML. You can find out more here about saving & exporting PDF documents in C#.

Here is a quick example for MVC and ASP.NET:

4.1. Export a PDF with MVC

/**
Export PDF with MVC
anchor-export-a-pdf-with-mvc
**/

return new FileStreamResult(stream, “application/pdf”)

{

   FileDownloadName = “downloadedfile.pdf”

};

/**
Export PDF with MVC
anchor-export-a-pdf-with-mvc
**/

return new FileStreamResult(stream, “application/pdf”)

{

   FileDownloadName = “downloadedfile.pdf”

};

'''
'''Export PDF with MVC
'''anchor-export-a-pdf-with-mvc
'''*

'INSTANT VB TODO TASK: The following line uses invalid syntax:
'Return New FileStreamResult(stream, "application/pdf”) { FileDownloadName = "downloadedfile.pdf” };

VB C#

4.1. Export a PDF with ASP.NET

/**
Export PDF with ASPNET
anchor-export-a-pdf-with-asp-net
**/
byte[] Binary = MyPDFDocument.BinaryData;

Response.Clear();

Response.ContentType = “application/octet-stream”;

Context.Response.OutputStream.Write(Binary, 0, Binary.Length);

Response.Flush();

/**
Export PDF with ASPNET
anchor-export-a-pdf-with-asp-net
**/
byte[] Binary = MyPDFDocument.BinaryData;

Response.Clear();

Response.ContentType = “application/octet-stream”;

Context.Response.OutputStream.Write(Binary, 0, Binary.Length);

Response.Flush();

'''
'''Export PDF with ASPNET
'''anchor-export-a-pdf-with-asp-net
'''*
Dim Binary() As Byte = MyPDFDocument.BinaryData

Response.Clear()

'INSTANT VB TODO TASK: The following line uses invalid syntax:
'Response.ContentType = "application/octet-stream”; Context.Response.OutputStream.Write(Binary, 0, Binary.Length); Response.Flush();

VB C#