PDF to MemoryStream C#

Q: What are the benefits of using MemoryStream for PDF operations in .NET?

Using MemoryStream for PDF operations in .NET allows for efficient memory management and increased security by keeping data in memory and avoiding disk writes, which is especially useful in web applications.

Q: Can I convert a MemoryStream back to a PDF file in C#?

Yes, a MemoryStream containing PDF data can be saved back to a PDF file using IronPDF by writing the stream's contents to a file.

Q: How can I export a PDF file in an MVC web application?

In an MVC web application, you can export a PDF by using a MemoryStream containing the PDF data and returning it as a FileStreamResult , setting the MIME type to 'application/pdf'.

Chaknith Bin

Updated:July 28, 2025

We can export PDF to MemoryStream in C# .NET without even touching the file system. This is possible through the MemoryStream object present inside the System.IO .NET namespace.

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First Step:

How to Convert MemoryStream to PDF in C#

Download the IronPDF C# library to convert MemoryStream to PDF
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

Save a PDF to Memory

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

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

:path=/static-assets/pdf/content-code-examples/how-to/pdf-to-memory-stream-to-stream.cs

using IronPdf;
using System.IO;

var renderer = new ChromePdfRenderer();

// Convert the URL into PDF
PdfDocument pdf = renderer.RenderUrlAsPdf("https://ironpdf.com/");

// Export PDF as Stream
MemoryStream pdfAsStream = pdf.Stream;

// Export PDF as Byte Array
byte[] pdfAsByte = pdf.BinaryData;

Imports IronPdf
Imports System.IO

Private renderer = New ChromePdfRenderer()

' Convert the URL into PDF
Private pdf As PdfDocument = renderer.RenderUrlAsPdf("https://ironpdf.com/")

' Export PDF as Stream
Private pdfAsStream As MemoryStream = pdf.Stream

' Export PDF as Byte Array
Private pdfAsByte() As Byte = pdf.BinaryData

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Serve a PDF to Web from Memory

To serve or export a PDF on the web, you need to send the PDF file as binary data instead of HTML. You can find more information in this guide on exporting and saving PDF documents in C#.

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

Export a PDF with MVC

The stream in the code snippet below is the binary data retrieved from IronPDF. The MIME type of the response is 'application/pdf', specifying the filename as 'download.pdf'.

using System.Web.Mvc;
using System.IO;

public ActionResult ExportPdf()
{
    // Assume pdfAsStream is a MemoryStream containing PDF data
    MemoryStream pdfAsStream = new MemoryStream();

    return new FileStreamResult(pdfAsStream, "application/pdf")
    {
        FileDownloadName = "download.pdf"
    };
}

using System.Web.Mvc;
using System.IO;

public ActionResult ExportPdf()
{
    // Assume pdfAsStream is a MemoryStream containing PDF data
    MemoryStream pdfAsStream = new MemoryStream();

    return new FileStreamResult(pdfAsStream, "application/pdf")
    {
        FileDownloadName = "download.pdf"
    };
}

Imports System.Web.Mvc
Imports System.IO

Public Function ExportPdf() As ActionResult
	' Assume pdfAsStream is a MemoryStream containing PDF data
	Dim pdfAsStream As New MemoryStream()

	Return New FileStreamResult(pdfAsStream, "application/pdf") With {.FileDownloadName = "download.pdf"}
End Function

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Export a PDF with ASP.NET

Similar to the example above, the stream is the binary data retrieved from IronPDF. The Response is then configured and flushed to ensure that it is sent to the client.

using System.IO;
using System.Web;

public class PdfHandler : IHttpHandler
{
    public void ProcessRequest(HttpContext context)
    {
        // Assume pdfAsStream is a MemoryStream containing PDF data
        MemoryStream pdfAsStream = new MemoryStream();

        context.Response.Clear();
        context.Response.ContentType = "application/octet-stream";
        context.Response.OutputStream.Write(pdfAsStream.ToArray(), 0, (int)pdfAsStream.Length);
        context.Response.Flush();
    }

    public bool IsReusable => false;
}

using System.IO;
using System.Web;

public class PdfHandler : IHttpHandler
{
    public void ProcessRequest(HttpContext context)
    {
        // Assume pdfAsStream is a MemoryStream containing PDF data
        MemoryStream pdfAsStream = new MemoryStream();

        context.Response.Clear();
        context.Response.ContentType = "application/octet-stream";
        context.Response.OutputStream.Write(pdfAsStream.ToArray(), 0, (int)pdfAsStream.Length);
        context.Response.Flush();
    }

    public bool IsReusable => false;
}

Imports System.IO
Imports System.Web

Public Class PdfHandler
	Implements IHttpHandler

	Public Sub ProcessRequest(ByVal context As HttpContext) Implements IHttpHandler.ProcessRequest
		' Assume pdfAsStream is a MemoryStream containing PDF data
		Dim pdfAsStream As New MemoryStream()

		context.Response.Clear()
		context.Response.ContentType = "application/octet-stream"
		context.Response.OutputStream.Write(pdfAsStream.ToArray(), 0, CInt(pdfAsStream.Length))
		context.Response.Flush()
	End Sub

	Public ReadOnly Property IsReusable() As Boolean Implements IHttpHandler.IsReusable
		Get
			Return False
		End Get
	End Property
End Class

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Frequently Asked Questions

How can I convert a PDF to a MemoryStream in C#?

You can convert a PDF to a MemoryStream in C# by using IronPDF. Load your PDF as a PdfDocument object, and use the PdfDocument.Stream property to export it as a System.IO.MemoryStream.

What are the methods to save a PDF to memory using IronPDF?

IronPDF provides two methods for saving a PDF to memory: using PdfDocument.Stream to export as a MemoryStream and PdfDocument.BinaryData to export as a byte array.

How can I serve a PDF as binary data in an ASP.NET application?

In an ASP.NET application, you can serve a PDF as binary data by configuring the Response object to send the MemoryStream with the MIME type 'application/pdf'.

Is it possible to create a PDF from HTML in C#?

Yes, you can render a PDF from an HTML string or file using IronPDF's PdfDocument object, which can then be converted into a MemoryStream.

How do I handle PDF files in memory for web applications?

You can handle PDF files entirely in memory for web applications using IronPDF by exporting the PDF to a MemoryStream and serving it directly to clients, avoiding file system interactions.

What are the benefits of using MemoryStream for PDF operations in .NET?

Using MemoryStream for PDF operations in .NET allows for efficient memory management and increased security by keeping data in memory and avoiding disk writes, which is especially useful in web applications.

Can I convert a MemoryStream back to a PDF file in C#?

Yes, a MemoryStream containing PDF data can be saved back to a PDF file using IronPDF by writing the stream's contents to a file.

How can I export a PDF file in an MVC web application?

In an MVC web application, you can export a PDF by using a MemoryStream containing the PDF data and returning it as a FileStreamResult, setting the MIME type to 'application/pdf'.

Chaknith Bin

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Software Engineer

Chaknith works on IronXL and IronBarcode. He has deep expertise in C# and .NET, helping improve the software and support customers. His insights from user interactions contribute to better products, documentation, and overall experience.