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USING IRONPDF

How to Open PDF in New Window ASP .NET C# with IronPDF

Curtis Chau
Curtis Chau
Published:

Introduction

Opening PDF files in a new window or browser tab is a common request in ASP.NET web applications. Developers often struggle with PDF documents that download automatically instead of displaying in the browser when users click a link. This frustrating behavior disrupts the user experience, especially when viewing reports, invoices, or documentation that users need to refer to while continuing their work on the current page.

IronPDF provides an elegant solution to this challenge, offering powerful PDF generation and display capabilities that integrate seamlessly with ASP.NET applications. Rather than wrestling with Response headers and Content-Disposition settings, developers can leverage IronPDF's ChromePdfRenderer to create and serve PDF files that open reliably in new browser tabs.

In this article, we'll take a look at how IronPDF is the answer to generating and displaying PDF files in your computer browser.

Why Do PDF Files Download Instead of Opening?

When serving PDF files through ASP.NET, the default behavior often results in downloads rather than browser display. This happens because of how the server sends the file to the browser through HTTP response headers. The Content-Disposition header particularly controls whether a PDF file opens inline or downloads.

Traditional ASP.NET code using Response.BinaryWrite with a byte array often sets headers that trigger downloads. Even when developers set Response.ContentType = "application/pdf", missing or incorrect Content-Disposition values cause the browser to download rather than display the PDF document. Additionally, different browsers handle PDF files inconsistently - while Adobe PDF Reader plugins might display files inline, mobile browsers often default to downloading.

The server side configuration becomes even more complex when dealing with dynamically generated PDF documents from HTML strings or data sources. Without the correct path and proper headers, achieving consistent cross-browser display becomes challenging. Many developers turn to Stack Overflow discussions seeking solutions to this persistent issue. Use the search function to find quick answers.

How Does IronPDF Simplify PDF Display?

IronPDF transforms the complex task of PDF generation and display into straightforward code. Using its Chrome-based rendering engine, IronPDF generates pixel-perfect PDF documents from HTML content while automatically handling the technical details that often trip up developers.

The library's ChromePdfRenderer class provides a modern approach to PDF creation. Instead of manually managing byte arrays and response streams, developers can generate PDFs from HTML strings, HTML files, or URLs with simple method calls. IronPDF handles the rendering process internally, ensuring consistent output across different environments.

Beyond basic generation, IronPDF offers extensive rendering options for customizing output, including paper size, margins, and JavaScript execution delays. This flexibility makes it ideal for creating everything from simple documents to complex reports with charts and dynamic content. We invite your comments on your preferred rendering settings.

How to Generate and Open PDF Files with IronPDF?

First, install IronPDF through NuGet Package Manager:

Install-Package IronPdf

Here's a complete example for ASP.NET Core that generates a PDF file and serves it to open in our browser tab:

using IronPdf;
using Microsoft.AspNetCore.Mvc;
public class PdfController : Controller
{
    [HttpGet]
    public IActionResult GeneratePdf()
    {
        // Create a new ChromePdfRenderer instance
        var renderer = new ChromePdfRenderer();
        // Generate PDF from HTML string with support for CSS and JavaScript
        string htmlString = @"
            <html>
                <body>
                    <h1>Sample PDF Document</h1>
                    <p>This PDF will open in a new browser tab.</p>
                    <p>Generated on: " + DateTime.Now.ToString() + @"</p>
                </body>
            </html>";
        // Create PDF document with proper format
        var PDF = renderer.RenderHtmlAsPdf(htmlString);
        // Convert to byte array for streaming
        byte[] pdfBytes = pdf.BinaryData;
        // Return file with inline display - key for opening in browser
        Response.Headers.Add("Content-Disposition", "inline; filename=document.pdf");
        Response.Headers.Add("Content-Length", pdfBytes.Length.ToString());
        return File(pdfBytes, "application/pdf");
    }
}
using IronPdf;
using Microsoft.AspNetCore.Mvc;
public class PdfController : Controller
{
    [HttpGet]
    public IActionResult GeneratePdf()
    {
        // Create a new ChromePdfRenderer instance
        var renderer = new ChromePdfRenderer();
        // Generate PDF from HTML string with support for CSS and JavaScript
        string htmlString = @"
            <html>
                <body>
                    <h1>Sample PDF Document</h1>
                    <p>This PDF will open in a new browser tab.</p>
                    <p>Generated on: " + DateTime.Now.ToString() + @"</p>
                </body>
            </html>";
        // Create PDF document with proper format
        var PDF = renderer.RenderHtmlAsPdf(htmlString);
        // Convert to byte array for streaming
        byte[] pdfBytes = pdf.BinaryData;
        // Return file with inline display - key for opening in browser
        Response.Headers.Add("Content-Disposition", "inline; filename=document.pdf");
        Response.Headers.Add("Content-Length", pdfBytes.Length.ToString());
        return File(pdfBytes, "application/pdf");
    }
}
IRON VB CONVERTER ERROR developers@ironsoftware.com
$vbLabelText   $csharpLabel

Displayed PDF

How to Open PDF in New Window ASP .NET C# with IronPDF: Image 1 - Image 1 of 4 related to How to Open PDF in New Window ASP .NET C# with IronPDF

The code above uses [HttpGet]. If you were creating this PDF after a user submitted a form, you would likely use the [HttpPost] attribute. This ensures your readers know the difference between a simple request and submitting a post request containing data.

The key to opening PDF files in the browser is setting the Content-Disposition header to "inline" rather than "attachment". This tells the browser to display the file rather than saving it by downloading it. The object sender and EventArgs e parameters in traditional ASP.NET button click events can trigger this controller action.

For WebForms applications using a Literal control or Literal tag, you can embed the PDF viewer directly on the current page:

protected void OpenPdf_Click(object sender, EventArgs e)
{
    var renderer = new ChromePdfRenderer();
    // Generate PDF document from HTML
    var PDF = renderer.RenderHtmlAsPdf("<h1>Invoice</h1><p>Your order details</p>");
    // Get byte array from PDF
    byte[] data = pdf.BinaryData;
    // Clear response and write PDF to browser
    Response.Clear();
    Response.ContentType = "application/pdf";
    Response.AddHeader("Content-Length", data.Length.ToString());
    Response.AddHeader("Content-Disposition", "inline; filename=invoice.pdf");
    Response.BinaryWrite(data);
    Response.End();
}
protected void OpenPdf_Click(object sender, EventArgs e)
{
    var renderer = new ChromePdfRenderer();
    // Generate PDF document from HTML
    var PDF = renderer.RenderHtmlAsPdf("<h1>Invoice</h1><p>Your order details</p>");
    // Get byte array from PDF
    byte[] data = pdf.BinaryData;
    // Clear response and write PDF to browser
    Response.Clear();
    Response.ContentType = "application/pdf";
    Response.AddHeader("Content-Length", data.Length.ToString());
    Response.AddHeader("Content-Disposition", "inline; filename=invoice.pdf");
    Response.BinaryWrite(data);
    Response.End();
}
IRON VB CONVERTER ERROR developers@ironsoftware.com
$vbLabelText   $csharpLabel

For users looking to create PDF forms or add digital signatures, IronPDF provides comprehensive support for these advanced features.

What About Browser Tab Control?

While server-side code determines whether a PDF displays inline, controlling whether it opens in the same tab or new tab requires client-side JavaScript. The target attribute in HTML links provides the simplest solution to open PDF in new window:

<a href="/Pdf/GeneratePdf" target="_blank">View File</a>
<a href="/Pdf/GeneratePdf" target="_blank">View File</a>
HTML

PDF Displayed in New Browser Tab

How to Open PDF in New Window ASP .NET C# with IronPDF: Image 2 - Opened PDF in new tab

For more control, JavaScript's window.open function works well with dynamically generated URLs to open PDF files in a new browser tab:

function openPdfInNewTab() {
    // Open PDF in new window using JavaScript
    window.open('/Pdf/GeneratePdf', '_blank');
    return false; // Prevent default form submission
}
function openPdfInNewTab() {
    // Open PDF in new window using JavaScript
    window.open('/Pdf/GeneratePdf', '_blank');
    return false; // Prevent default form submission
}
JAVASCRIPT

In ASP.NET web applications, combine this with a button control:

<asp:Button ID="btnViewPdf" runat="server"
            OnClientClick="window.open('/Pdf/GeneratePdf', '_blank'); return false;"
            Text="Open PDF in New Tab" />
<asp:Button ID="btnViewPdf" runat="server"
            OnClientClick="window.open('/Pdf/GeneratePdf', '_blank'); return false;"
            Text="Open PDF in New Tab" />
IRON VB CONVERTER ERROR developers@ironsoftware.com
$vbLabelText   $csharpLabel

Note: When using JavaScript's window.open(), the second argument '_blank' is what opens the document in a new, separate window or tab. The name of the new window can be left blank if you don't need to specify one.

The HTML object tag provides another option for embedding PDF documents directly in the page, especially useful when users have Adobe PDF Reader installed:

<object data="/Pdf/GeneratePdf" type="application/pdf" width="100%" height="600px">
    <embed src="/Pdf/GeneratePdf" type="application/pdf" />
    <p>Your browser doesn't support embedded PDF documents.
       <a href="/Pdf/GeneratePdf" target="_blank">View PDF File</a>
    </p>
</object>
<object data="/Pdf/GeneratePdf" type="application/pdf" width="100%" height="600px">
    <embed src="/Pdf/GeneratePdf" type="application/pdf" />
    <p>Your browser doesn't support embedded PDF documents.
       <a href="/Pdf/GeneratePdf" target="_blank">View PDF File</a>
    </p>
</object>
HTML

Embedded PDF File

How to Open PDF in New Window ASP .NET C# with IronPDF: Image 3 - Embedded PDF file

This approach works well when Adobe PDF Reader or similar plugins are available, though modern browsers increasingly support native PDF display without additional software. According to Microsoft's documentation, proper HTTP headers combined with client-side code provide the most reliable cross-browser solution. Please note the importance of the target="_blank" attribute.

How to Handle Different File Sources?

IronPDF excels at handling various input sources beyond HTML strings. When working with existing PDF files or generating from different data formats, the library provides flexible options for serving PDF documents to users.

For loading existing PDF documents from the correct path:

public IActionResult ViewFile(string fileName)
{
    // Ensure correct path to PDF file
    string path = Path.Combine(_webHostEnvironment.WebRootPath, "pdfs", fileName);
    // Load existing PDF document
    var PDF = PdfDocument.FromFile(path);
    // Optionally add additional information to the PDF
    pdf.AddPage(renderer.RenderHtmlAsPdf("<h2>Additional Information</h2>"));
    // Convert to stream for browser display
    var stream = pdf.Stream;
    byte[] bytes = stream.ToArray();
    // Set headers for inline display in new browser tab
    Response.Headers.Add("Content-Disposition", "inline; filename=" + fileName);
    Response.Headers.Add("Content-Length", bytes.Length.ToString());
    return File(bytes, "application/pdf");
}
public IActionResult ViewFile(string fileName)
{
    // Ensure correct path to PDF file
    string path = Path.Combine(_webHostEnvironment.WebRootPath, "pdfs", fileName);
    // Load existing PDF document
    var PDF = PdfDocument.FromFile(path);
    // Optionally add additional information to the PDF
    pdf.AddPage(renderer.RenderHtmlAsPdf("<h2>Additional Information</h2>"));
    // Convert to stream for browser display
    var stream = pdf.Stream;
    byte[] bytes = stream.ToArray();
    // Set headers for inline display in new browser tab
    Response.Headers.Add("Content-Disposition", "inline; filename=" + fileName);
    Response.Headers.Add("Content-Length", bytes.Length.ToString());
    return File(bytes, "application/pdf");
}
IRON VB CONVERTER ERROR developers@ironsoftware.com
$vbLabelText   $csharpLabel

Opened PDF

How to Open PDF in New Window ASP .NET C# with IronPDF: Image 4 - Viewing an existing PDF document

Working with byte arrays from a database or external source requires careful handling to ensure the PDF opens correctly:

public IActionResult DisplayFromDatabase(int documentId)
{
    // Retrieve byte array from database or system
    byte[] pdfData = GetPdfFromDatabase(documentId);
    // Load PDF document from bytes
    var PDF = PdfDocument.FromBytes(pdfData);
    // Optionally sign or modify the PDF
    // pdf.SignWithDigitalCertificate(...);
    // Set response headers for inline display
    Response.Headers.Add("Content-Disposition",
                        $"inline; filename=document_{documentId}.pdf");
    Response.Headers.Add("Content-Length", pdfData.Length.ToString());
    // Return file to open in browser
    return File(pdfData, "application/pdf");
}
public IActionResult DisplayFromDatabase(int documentId)
{
    // Retrieve byte array from database or system
    byte[] pdfData = GetPdfFromDatabase(documentId);
    // Load PDF document from bytes
    var PDF = PdfDocument.FromBytes(pdfData);
    // Optionally sign or modify the PDF
    // pdf.SignWithDigitalCertificate(...);
    // Set response headers for inline display
    Response.Headers.Add("Content-Disposition",
                        $"inline; filename=document_{documentId}.pdf");
    Response.Headers.Add("Content-Length", pdfData.Length.ToString());
    // Return file to open in browser
    return File(pdfData, "application/pdf");
}
IRON VB CONVERTER ERROR developers@ironsoftware.com
$vbLabelText   $csharpLabel

For scenarios requiring HTML object tag integration with Literal controls, IronPDF supports advanced HTML to PDF conversion including CSS styling, images, and even web fonts. The library also provides comprehensive troubleshooting guides for achieving pixel-perfect results. This allows you to easily access the file data.

Conclusion

Learning how to open PDF in new window ASP .NET C# becomes straightforward with IronPDF. By handling the complexities of PDF generation and properly setting HTTP headers, developers can ensure consistent display across browsers while maintaining clean, maintainable code in your programs. Whether you're working with HTML strings, existing PDF documents, or byte arrays from databases, IronPDF provides the tools needed to deliver PDF content exactly how users expect it.

Start your free trial of IronPDF today to implement professional PDF functionality in your ASP.NET applications. For production deployment, explore our licensing options that include comprehensive support and additional features for enterprise web applications.

Frequently Asked Questions

How can I open PDFs in new browser tabs using ASP.NET and C#?

To open PDFs in new browser tabs using ASP.NET and C#, you can use IronPDF to generate and stream your PDF documents. By setting the correct HTTP headers in your response, you ensure that the PDF opens in a new tab instead of downloading.

What is the advantage of displaying PDFs in browser tabs?

Displaying PDFs in browser tabs enhances user experience by allowing users to view documents directly in their browser without needing to download them first. This approach also keeps users on your site longer and maintains the context of their browsing session.

How do I set HTTP headers to open PDFs in a new tab?

To set HTTP headers for opening PDFs in a new tab, ensure you use 'Content-Disposition: inline; filename="yourfile.pdf"'. This header suggests to the browser that it should try to display the PDF inline, within the browser window.

Can JavaScript be used to open PDFs in new windows?

Yes, JavaScript can be used to open PDFs in new windows. By creating a hyperlink element with the target attribute set to '_blank', you can ensure the PDF opens in a new browser tab or window.

Does IronPDF support various PDF functionalities in ASP.NET?

Yes, IronPDF supports a wide range of PDF functionalities in ASP.NET, including creation, editing, and rendering PDFs, as well as opening them in browser tabs.

Is it possible to customize the appearance of PDFs displayed in browser tabs?

While customizing the appearance of PDFs themselves is done through the PDF generation process, the way they are displayed in browser tabs is dependent on the browser's PDF viewer capabilities. IronPDF helps in generating high-quality PDFs that render well in browsers.

What role does IronPDF play in improving PDF display in web applications?

IronPDF enhances PDF display in web applications by providing developers with tools to generate and manipulate PDFs programmatically, ensuring they are optimized for display in browsers and meet specific user needs.

Can IronPDF handle large PDF files efficiently?

Yes, IronPDF is designed to handle large PDF files efficiently, offering performance optimizations that ensure quick rendering and minimal load times when opening PDFs in new browser tabs.

How does IronPDF ensure compatibility across different browsers?

IronPDF generates standard-compliant PDF files that are compatible across different browsers, ensuring that users have a consistent viewing experience regardless of their browser choice.

Curtis Chau
Curtis Chau
  Chat with engineering team now
Technical Writer

Curtis Chau holds a Bachelor’s degree in Computer Science (Carleton University) and specializes in front-end development with expertise in Node.js, TypeScript, JavaScript, and React. Passionate about crafting intuitive and aesthetically pleasing user interfaces, Curtis enjoys working with modern frameworks and creating well-structured, visually appealing manuals.

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