How to Create PDF in ASP.NET Core: Step-by-Step Guide

Creating PDFs in ASP.NET applications is a common requirement, whether you're generating invoices, reports, forms, or exporting dynamic content. To streamline this process, you can utilize Spire.PDF for .NET, a professional and lightweight library that enables developers to easily create and manipulate PDF documents programmatically, without the need for complex APIs or third-party printer drivers.

In this tutorial, we’ll show you how to create PDF documents in an ASP.NET Core Web application using Spire.PDF for .NET, with examples of creating a PDF from scratch and converting HTML to PDF.

On this page:

• Why Use Spire.PDF for .NET?
• Step-by-Step: Generate PDF in ASP.NET Core Web App
• Create PDF from HTML in ASP.NET Core
• Best Practices for ASP.NET PDF Generation
• Conclusion
• FAQs

Why Use Spire.PDF for .NET?

Step-by-Step: Generate PDF in ASP.NET Core Web App

Step 1. Create a New ASP.NET Core Web App

• Open Visual Studio .
• Select Create a new project .
• Choose ASP.NET Core Web App (Model-View-Controller) → Click Next .
• Enter a project name, e.g., PdfDemoApp.
• Select your target framework (e.g., . NET 6 , 7 , or 8 ).
• Click Create .

Step 2. Install Spire.PDF via NuGet

• Right-click on your project → Manage NuGet Packages .
• Search for Spire.PDF .
• Install the package Spire.PDF (latest stable version).

Or install using the Package Manager Console :

Install-Package Spire.PDF

Step 3. Add a Controller for PDF Generation

• Right-click on the Controllers folder → Add → Controller → MVC Controller – Empty .
• Name it: PdfController.cs.
• Replace the default code with this:

using Microsoft.AspNetCore.Mvc;
using Spire.Pdf;
using Spire.Pdf.Graphics;
using System.Drawing;

namespace PdfDemoApp.Controllers
{
    public class PdfController : Controller
    {
        public IActionResult CreatePdf()
        {
            // Create a new PDF document
            PdfDocument doc = new PdfDocument();
            PdfPageBase page = doc.Pages.Add(PdfPageSize.A4, new PdfMargins(40));

            // Draw text on the page
            PdfFont font = new PdfFont(PdfFontFamily.Helvetica, 25f);
            PdfSolidBrush brush = new PdfSolidBrush(Color.Black);
            page.Canvas.DrawString("Hello from ASP.NET Core!", font, brush, 10, 50);

            // Save to memory stream
            using (MemoryStream ms = new MemoryStream())
            {
                doc.SaveToStream(ms);
                doc.Close();
                ms.Position = 0;

                // Return PDF file
                return File(ms.ToArray(), "application/pdf", "Generated.pdf");
            }
        }
    }
}

Step 4: (Optional) Add a Button or Link in Your View

Open Views/Home/Index.cshtml (or whichever view is your homepage).

Add a button or link like this:

<div>
    <a asp-controller="Pdf" asp-action="CreatePdf" class="btn btn-primary">
        Create PDF from Scratch
    </a>
</div>

This uses ASP.NET Core tag helpers to generate the correct route (/Pdf/CreatePdf).

Step 5. Run and Test

• Press F5 to run your app.
• On the home page, click the "Create PDF from Scratch" button. This will call the CreatePdf method in PdfController and trigger a download of the generated PDF.
• If you didn’t add the button, you can still run the CreatePdf method directly by visiting this URL in your browser:

https://localhost:xxxx/Pdf/CreatePdf

(where xxxx is your local port number).

Output:

In addition to text, Spire.PDF supports adding a wide range of elements to PDF, such as images, shapes, tables, lists, hyperlinks, annotations, and watermarks. For more details and advanced usage, check the .NET PDF Tutorials.

Create PDF from HTML in ASP.NET Core

Spire.PDF allows you to convert HTML content directly into PDF files. This feature is particularly useful for generating invoices, reports, receipts, or exporting styled web pages with consistent formatting.

To render HTML as PDF, Spire.PDF relies on an external rendering engine. You can choose between Qt WebEngine or Google Chrome . In this guide, we’ll use Qt WebEngine .

Setup the Qt plugin:

1. Download the Qt WebEngine plugin for your operating system:

   • Windows x86
   • Windows x64
   • Linux x64
   • Mac x64

2. Extract the package to obtain the plugins directory, e.g.: C:\plugins-windows-x64\plugins

3. Register the plugin path inyour code:

HtmlConverter.PluginPath = @"C:\plugins-windows-x64\plugins";

Once the plugin is ready, you can follow the steps from the previous section and add the code snippet below to your controller to generate PDF output from HTML content.

using Microsoft.AspNetCore.Mvc;
using Spire.Additions.Qt;
using Spire.Pdf.Graphics;
using System.Drawing;

namespace PdfDemoApp.Controllers
{
    public class PdfController : Controller
    {
        [HttpGet]
        public IActionResult HtmlToPdf()
        {
            // Example HTML string
            string html = @"
                <html>
                  <head>
                    <style>
                      body { font-family: Arial, sans-serif; }
                      h1 { color: #2563eb; }
                    </style>
                  </head>
                  <body>
                    <h1>ASP.NET Core: Create PDF from HTML</h1>
                    <p>This PDF was generated using the Qt-based converter.</p>
                  </body>
                </html>";

            // Path to the Qt plugin folder
            // ⚠️ Ensure this folder exists on your server/deployment environment
            string pluginPath = @"C:\plugins-windows-x64\plugins";
            HtmlConverter.PluginPath = pluginPath;

            // Create a temp file path (on server side)
            string tempFile = Path.GetTempFileName();

            // Convert HTML string → PDF using Qt
            HtmlConverter.Convert(
                html,
                tempFile,
                enableJavaScript: true,
                timeout: 100000,                        // milliseconds
                pageSize: new SizeF(595, 842),          // A4 page size in points
                margins: new PdfMargins(40),            // 40pt margins
                LoadHtmlType.SourceCode                 // Load from HTML string
            );

            // Read the generated PDF into memory
            byte[] fileBytes = System.IO.File.ReadAllBytes(tempFile);

            // Clean up temp file
            System.IO.File.Delete(tempFile);

            // Return PDF to browser as download
            return File(fileBytes, "application/pdf", "HtmlToPdf.pdf");
        }
    }
}

Output:

This example converts inline HTML into a properly formatted PDF. You can also load external HTML files or URLs - see our detailed guide on Convert HTML to PDF in C# for more information.

Best Practices for ASP.NET PDF Generation

• Use memory streams instead of disk storage for performance and scalability.
• Cache static PDFs (like terms & conditions or forms) to reduce server load.
• Use HTML-to-PDF for dynamic reports with CSS styling.
• Consider templates (like Word-to-PDF with Spire.Doc) when documents have complex layouts.
• Secure sensitive PDFs with password protection or access permissions.

Conclusion

With Spire.PDF for .NET, you can easily generate PDF in ASP.NET Core applications. Whether you’re creating PDFs from scratch or performing HTML-to-PDF conversion in C# , Spire.PDF provides a reliable, developer-friendly solution—no external dependencies required.

If you also need to generate PDFs from Word documents, that feature is available via Spire.Doc for .NET, another product in the Spire family. Together, they cover the full range of PDF document generation scenarios.

By integrating these tools, developers can streamline workflows, reduce reliance on Adobe or other third-party components, and ensure consistent, professional-quality output. This makes your ASP.NET PDF solutions more scalable, maintainable, and ready for enterprise use.

FAQs

Q1. Do I need Adobe Acrobat installed on the server?

No. Spire.PDF is a standalone library and works independently of Adobe Acrobat.

Q2. Can I generate PDFs from both raw content and HTML?

Yes. You can build documents programmatically (drawing text, shapes, tables) or convert HTML pages to PDF.

Q3. Can I convert Word documents to PDF with Spire.PDF?

No. Word-to-PDF is supported by Spire.Doc for .NET, not Spire.PDF. You can use them together if your project requires it.

Q4. How can I protect generated PDFs?

Spire.PDF supports setting passwords, permissions, and digital signatures for document security.

Q5. Does Spire.PDF support ASP.NET Framework?

Yes. It works with both ASP.NET Core and ASP.NET Framework.

Get a Free License

To fully experience the capabilities of Spire.PDF for .NET without any evaluation limitations, you can request a free 30-day trial license.