How to convert HTML to PDF in ASP .NET using C#

In modern web applications, generating documents from HTML content is a common requirement. Whether you need to create invoices, reports, or any other types of documents, converting HTML to PDF can be accomplished efficiently with the IronPDF library in ASP.NET using C#.

Today, we will explore how to set up IronPDF and use it to convert HTML content into a PDF document.

How to Convert HTML to PDF in ASP.NET with IronPDF

1. Create an ASP.NET project using Visual Studio or your IDE of choice.
2. Install IronPDF and set up your license key.
3. Create a new controller or page where you want to handle the PDF conversion.
4. Write your conversion logic within the controller.
5. Configure routing to allow access to your PDF generation action.

An Overview of IronPDF

IronPDF is a powerful PDF library that allows developers to read, create, and manipulate PDF documents. With a rich feature set and a quick, simple installation process, you can take your PDF projects to the next level in no time thanks to IronPDF. Its intuitive API is easy to learn, making it an ideal choice if you are looking to generate dynamic PDF documents, perform PDF security tasks, PDF annotations, etc., directly from your web application.

Features

• PDF conversion: IronPDF can convert HTML files to PDF, with its full support for modern web standards. You can be assured that IronPDF will consistently return pixel-perfect PDFs from your HTML pages. IronPDF can also convert PDF files from other formats such as DOCX, images, RTF, and more.
• PDF Generation: With IronPDF, you can generate PDFs from any web page, ASPX file, HTML string, or more.
• Security features: With IronPDF, you can always be assured that any sensitive PDF files are secure thanks to its security features. Use IronPDF to encrypt your PDF files, set passwords, and set permissions for your PDF files.
• PDF editing features: With IronPDF you can process existing PDF documents, edit them, and read PDF files with ease. IronPDF offers editing features such as adding headers and footers, stamping text and images onto the PDF pages, adding custom watermarks to the PDF, working with PDF forms, and splitting or merging PDF files.

Prerequisites

Before you start, ensure you have:

• Visual Studio or another C# development environment set up.
• IronPDF library installed. You can get it from NuGet or directly from the IronPDF website.

Create a New ASP.NET Project

Launch Visual Studio and select the ASP.NET project type that best suits your needs. For today's example, I will be creating an ASP.NET Core Web App (Model-view Controller).

Then, enter the name for your project and choose the location to house the project.

Finally, choose your .NET Framework for the project, and change any additional settings for the project such as the authentication type, or enabling container support and docker.

Create a Controller

To create a new controller to house our HTML to PDF code within, first right-click on the "Controllers" folder in the solution explorer and choose "Add -> Controller".

This will prompt a new window to open, where you can choose what form of controller you want to add to the project. We have picked an empty MVC Controller.

Finally, we give the new Controller a name and click "Add" to add it to our project.

Add HTML to PDF Conversion Code

Now that we have created our ASP.NET project, we can begin writing the code for converting HTML file content to a PDF. We will start with a simple example of HTML string to PDF, before looking at converting HTML content with customization.

using IronPdf;
using Microsoft.AspNetCore.Mvc;

namespace IronPdfTest.Controllers
{
    public class PdfController : Controller
    {
        // Action method to generate a PDF from HTML content
        public IActionResult GeneratePdf()
        {
            // String of HTML code to be converted to PDF
            string htmlContent = "<h1>Hello, IronPDF!</h1><p>This is a PDF generated from HTML.</p>";

            // Creating a renderer to convert the HTML string to PDF
            ChromePdfRenderer renderer = new ChromePdfRenderer();

            // Convert HTML string to PDF
            PdfDocument pdf = renderer.RenderHtmlAsPdf(htmlContent);

            // Return the generated PDF file
            return File(pdf.BinaryData, "application/pdf", "generatedDocument.pdf");
        }
    }
}

using IronPdf;
using Microsoft.AspNetCore.Mvc;

namespace IronPdfTest.Controllers
{
    public class PdfController : Controller
    {
        // Action method to generate a PDF from HTML content
        public IActionResult GeneratePdf()
        {
            // String of HTML code to be converted to PDF
            string htmlContent = "<h1>Hello, IronPDF!</h1><p>This is a PDF generated from HTML.</p>";

            // Creating a renderer to convert the HTML string to PDF
            ChromePdfRenderer renderer = new ChromePdfRenderer();

            // Convert HTML string to PDF
            PdfDocument pdf = renderer.RenderHtmlAsPdf(htmlContent);

            // Return the generated PDF file
            return File(pdf.BinaryData, "application/pdf", "generatedDocument.pdf");
        }
    }
}

Imports IronPdf
Imports Microsoft.AspNetCore.Mvc

Namespace IronPdfTest.Controllers
	Public Class PdfController
		Inherits Controller

		' Action method to generate a PDF from HTML content
		Public Function GeneratePdf() As IActionResult
			' String of HTML code to be converted to PDF
			Dim htmlContent As String = "<h1>Hello, IronPDF!</h1><p>This is a PDF generated from HTML.</p>"

			' Creating a renderer to convert the HTML string to PDF
			Dim renderer As New ChromePdfRenderer()

			' Convert HTML string to PDF
			Dim pdf As PdfDocument = renderer.RenderHtmlAsPdf(htmlContent)

			' Return the generated PDF file
			Return File(pdf.BinaryData, "application/pdf", "generatedDocument.pdf")
		End Function
	End Class
End Namespace

ASP.NET MVC uses controllers to handle user requests. When a user navigates to a specific URL, ASP.NET will call a method in the controller associated with that route.

• PdfController is a class inheriting from Controller, meaning it can handle web requests and send responses.
• The GeneratePdf method inside this controller will handle a request to convert HTML into a PDF and return the result.

When a user visits a URL linked to the GeneratePdf action, the method executes.

• IActionResult: This is the return type, representing the response that the web application will send back to the user. It could be a view (HTML page), file download, etc. In this case, it's a PDF file.

  • GeneratePdf() Method:

  • Inside the method, we define a string htmlContent that contains the HTML you want to convert to a PDF. For example, "<h1>Hello, IronPDF!</h1><p>This is a PDF generated from HTML.</p>".

  • We create a new instance of ChromePdfRenderer, which handles the conversion of HTML to PDF.

  • The method RenderHtmlAsPdf() takes the HTML string and returns a PDF object.

Configure Routing

In an ASP.NET MVC application, you define routes that map URLs to controller methods (actions). For example, if you navigate to /Pdf/GeneratePdf in the browser, ASP.NET will look for the PdfController and call its GeneratePdf method. Ensure your routing configuration allows access to the GeneratePdf action. If you are using ASP.NET Core MVC, this is usually configured automatically. If you are using Web API, make sure your routes are properly set up.

Custom PDF Output

Now that we have the basics down, let's look at creating a PDF file from HTML content with some customization settings set for the output PDF. IronPDF provides a powerful set of PDF customization tools, such as margins, headers/footers, custom PDF sizing, and more.

using IronPdf;
using Microsoft.AspNetCore.Mvc;

namespace IronPdfTest.Controllers
{
    // Controller for our PDF converter
    public class PdfController : Controller
    {
        // Action method to generate a customized PDF from HTML content
        public IActionResult GeneratePdf()
        {
            // String of HTML code to be converted to PDF
            string htmlContent = "<h1>Hello, IronPDF!</h1><p>This is a PDF generated from HTML.</p>";

            // Creating a renderer to convert the URL to PDF
            ChromePdfRenderer renderer = new ChromePdfRenderer();

            // Creating the cover page
            PdfDocument cover = renderer.RenderHtmlAsPdf("<h1>Cover Page</h1>");

            // Adding custom options for our final PDF
            renderer.RenderingOptions.PaperOrientation = IronPdf.Rendering.PdfPaperOrientation.Landscape;
            renderer.RenderingOptions.PaperSize = IronPdf.Rendering.PdfPaperSize.A3;
            renderer.RenderingOptions.TextHeader.CenterText = "IronPDF";
            renderer.RenderingOptions.TextHeader.FontSize = 12;
            renderer.RenderingOptions.MarginTop = 20;
            renderer.RenderingOptions.FirstPageNumber = 2;

            // Creating our main PDF
            PdfDocument pdf = renderer.RenderHtmlAsPdf(htmlContent);

            // Appending the cover to the main PDF
            pdf.InsertPdf(cover, 0);

            // Return the customized generated PDF file
            return File(pdf.BinaryData, "application/pdf", "generatedDocument.pdf");
        }
    }
}

using IronPdf;
using Microsoft.AspNetCore.Mvc;

namespace IronPdfTest.Controllers
{
    // Controller for our PDF converter
    public class PdfController : Controller
    {
        // Action method to generate a customized PDF from HTML content
        public IActionResult GeneratePdf()
        {
            // String of HTML code to be converted to PDF
            string htmlContent = "<h1>Hello, IronPDF!</h1><p>This is a PDF generated from HTML.</p>";

            // Creating a renderer to convert the URL to PDF
            ChromePdfRenderer renderer = new ChromePdfRenderer();

            // Creating the cover page
            PdfDocument cover = renderer.RenderHtmlAsPdf("<h1>Cover Page</h1>");

            // Adding custom options for our final PDF
            renderer.RenderingOptions.PaperOrientation = IronPdf.Rendering.PdfPaperOrientation.Landscape;
            renderer.RenderingOptions.PaperSize = IronPdf.Rendering.PdfPaperSize.A3;
            renderer.RenderingOptions.TextHeader.CenterText = "IronPDF";
            renderer.RenderingOptions.TextHeader.FontSize = 12;
            renderer.RenderingOptions.MarginTop = 20;
            renderer.RenderingOptions.FirstPageNumber = 2;

            // Creating our main PDF
            PdfDocument pdf = renderer.RenderHtmlAsPdf(htmlContent);

            // Appending the cover to the main PDF
            pdf.InsertPdf(cover, 0);

            // Return the customized generated PDF file
            return File(pdf.BinaryData, "application/pdf", "generatedDocument.pdf");
        }
    }
}

Imports IronPdf
Imports Microsoft.AspNetCore.Mvc

Namespace IronPdfTest.Controllers
	' Controller for our PDF converter
	Public Class PdfController
		Inherits Controller

		' Action method to generate a customized PDF from HTML content
		Public Function GeneratePdf() As IActionResult
			' String of HTML code to be converted to PDF
			Dim htmlContent As String = "<h1>Hello, IronPDF!</h1><p>This is a PDF generated from HTML.</p>"

			' Creating a renderer to convert the URL to PDF
			Dim renderer As New ChromePdfRenderer()

			' Creating the cover page
			Dim cover As PdfDocument = renderer.RenderHtmlAsPdf("<h1>Cover Page</h1>")

			' Adding custom options for our final PDF
			renderer.RenderingOptions.PaperOrientation = IronPdf.Rendering.PdfPaperOrientation.Landscape
			renderer.RenderingOptions.PaperSize = IronPdf.Rendering.PdfPaperSize.A3
			renderer.RenderingOptions.TextHeader.CenterText = "IronPDF"
			renderer.RenderingOptions.TextHeader.FontSize = 12
			renderer.RenderingOptions.MarginTop = 20
			renderer.RenderingOptions.FirstPageNumber = 2

			' Creating our main PDF
			Dim pdf As PdfDocument = renderer.RenderHtmlAsPdf(htmlContent)

			' Appending the cover to the main PDF
			pdf.InsertPdf(cover, 0)

			' Return the customized generated PDF file
			Return File(pdf.BinaryData, "application/pdf", "generatedDocument.pdf")
		End Function
	End Class
End Namespace

Conclusion

Today we have taken a closer look at how HTML to PDF conversion can be used with ASP.NET, and explored the process of creating PDF files from HTML within an ASP.NET project. By following the steps outlined above, you can easily integrate PDF generation into your web applications, allowing you to create high-quality, printable documents from HTML content.

IronPDF sports a rich set of features that can be leveraged to produce high-quality PDF documents. For more advanced features and detailed customization, refer to the IronPDF documentation. With its fast installation, you can have IronPDF set up within your project in no time.