USING IRONPDF

How to Convert HTML to PDF C# Without Library

Name: IronPDF
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Chipego Kalinda

April 3, 2025

Introduction

When it comes to converting HTML to PDF in C#, developers might consider using native .NET features without relying on external libraries. While this approach can be viable in certain scenarios, it comes with its own set of advantages and challenges. This article will explore the process, the pros and cons, and discuss why a library like IronPDF might be a better option.

How It Works

Using built-in .NET tools, you can achieve HTML to PDF conversion by rendering the HTML content and printing it using the WebBrowser control and the PrintDocument class. Here's a simplified workflow:

Write the HTML content to a temporary file.
Load the HTML into a WebBrowser control for rendering.
Use the PrintDocument class to create a print job that outputs the rendered content.

While this approach avoids external dependencies, it involves working with low-level components and manually defining printing logic.

If you want to convert HTML to PDF in C# without using any external libraries, you can use the built-in .NET features like System.IO and System.Drawing.Printing to render the HTML and then create a PDF. Below is a basic example to help you get started:

How to convert HTML to PDF c# without library

How to Convert HTML to PDF C# Without Library: Figure 1 Add from PixabayUpload

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using System;
using System.IO;
using System.Windows.Forms; // You need to add a reference to System.Windows.Forms
using System.Drawing.Printing;
class Program
{
    [STAThread] // Required for using WebBrowser control
    static void Main()
    {
        // HTML content
        string htmlContent = "<html><body><h1>Hello, World!</h1></body></html>";
        // Write HTML content to a temporary file
        string tempFilePath = Path.Combine(Path.GetTempPath(), "temp.html");
        File.WriteAllText(tempFilePath, htmlContent);
        // Create WebBrowser to render HTML
        WebBrowser webBrowser = new WebBrowser();
        webBrowser.DocumentCompleted += (sender, e) => 
        {
            // Print the document to a file
            PrintDocument printDoc = new PrintDocument();
            printDoc.PrintPage += (s, args) =>
            {
                args.Graphics.DrawString(htmlContent, new Font("Arial", 12), Brushes.Black, new PointF(100, 100));
            };
            // Save as PDF (or use PrintDialog for physical printing)
            printDoc.PrintController = new StandardPrintController(); // Silent print
            printDoc.Print(); // You'd need to replace this with PDF creation logic.
            Application.ExitThread(); // Close the application
        };
        // Load the HTML file
        webBrowser.Url = new Uri(tempFilePath);
        Application.Run();
    }
}

using System;
using System.IO;
using System.Windows.Forms; // You need to add a reference to System.Windows.Forms
using System.Drawing.Printing;
class Program
{
    [STAThread] // Required for using WebBrowser control
    static void Main()
    {
        // HTML content
        string htmlContent = "<html><body><h1>Hello, World!</h1></body></html>";
        // Write HTML content to a temporary file
        string tempFilePath = Path.Combine(Path.GetTempPath(), "temp.html");
        File.WriteAllText(tempFilePath, htmlContent);
        // Create WebBrowser to render HTML
        WebBrowser webBrowser = new WebBrowser();
        webBrowser.DocumentCompleted += (sender, e) => 
        {
            // Print the document to a file
            PrintDocument printDoc = new PrintDocument();
            printDoc.PrintPage += (s, args) =>
            {
                args.Graphics.DrawString(htmlContent, new Font("Arial", 12), Brushes.Black, new PointF(100, 100));
            };
            // Save as PDF (or use PrintDialog for physical printing)
            printDoc.PrintController = new StandardPrintController(); // Silent print
            printDoc.Print(); // You'd need to replace this with PDF creation logic.
            Application.ExitThread(); // Close the application
        };
        // Load the HTML file
        webBrowser.Url = new Uri(tempFilePath);
        Application.Run();
    }
}

Imports System
Imports System.IO
Imports System.Windows.Forms ' You need to add a reference to System.Windows.Forms
Imports System.Drawing.Printing
Friend Class Program
	<STAThread>
	Shared Sub Main()
		' HTML content
		Dim htmlContent As String = "<html><body><h1>Hello, World!</h1></body></html>"
		' Write HTML content to a temporary file
		Dim tempFilePath As String = Path.Combine(Path.GetTempPath(), "temp.html")
		File.WriteAllText(tempFilePath, htmlContent)
		' Create WebBrowser to render HTML
		Dim webBrowser As New WebBrowser()
		AddHandler webBrowser.DocumentCompleted, Sub(sender, e)
			' Print the document to a file
			Dim printDoc As New PrintDocument()
			AddHandler printDoc.PrintPage, Sub(s, args)
				args.Graphics.DrawString(htmlContent, New Font("Arial", 12), Brushes.Black, New PointF(100, 100))
			End Sub
			' Save as PDF (or use PrintDialog for physical printing)
			printDoc.PrintController = New StandardPrintController() ' Silent print
			printDoc.Print() ' You'd need to replace this with PDF creation logic.
			Application.ExitThread() ' Close the application
		End Sub
		' Load the HTML file
		webBrowser.Url = New Uri(tempFilePath)
		Application.Run()
	End Sub
End Class

Code Explanation

The WebBrowser control is used to render the HTML.
The PrintDocument class is used to define the printing behavior.
This example doesn't directly create a PDF; you would need to extend it to integrate raw PDF creation logic, such as drawing text and shapes manually, or work with streams.

This approach is limited and can become complex for large or styled HTML documents. If your use case allows, using a library like IronPDF is usually much more efficient and feature-rich.

Pros and Cons of Using Built-In .NET Features

Pros

No External Dependencies: Avoiding external libraries can reduce the complexity of managing third-party dependencies in your project.
Free of Cost: Since this method uses only native .NET components, there are no licensing fees or additional costs.
Fine-Tuned Control: You have complete control over how the content is rendered and printed, which allows for custom handling.

Cons

Limited Features: The built-in .NET tools lack the capabilities to accurately render complex HTML, CSS, or JavaScript. Advanced layouts, responsive designs, or dynamic content may not be supported.
Time-Consuming Implementation: You need to write custom code to handle rendering, pagination, and PDF creation, which could lead to higher development costs.
Low Scalability: For large-scale or high-performance applications, this approach may be inefficient and prone to bottlenecks.
No Native PDF Support: The workflow does not directly create PDFs; you would need to implement custom logic to generate a PDF file from the print output.

Introduction to IronPDF

How to Convert HTML to PDF C# Without Library: Figure 2 Add from PixabayUpload

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Add image alt text

IronPDF is a .NET library that allows developers to convert HTML to PDF with ease. It supports a wide range of features, including CSS, JavaScript, and even embedded images. With IronPDF, you can create PDFs that look exactly like your HTML web pages, ensuring a seamless transition between formats. This library is particularly useful for web applications that need to generate dynamic PDF documents on the fly.

IronPDF allows developers to seamlessly integrate PDF functionality into .NET applications without needing to manually manage PDF file structures. IronPDF leverages the Chrome-based rendering engine to convert an HTML pages (including complex CSS, JavaScript, and images) into well-structured PDF documents. It can be used for generating reports, invoices, eBooks, or any type of document that needs to be presented in PDF format.

IronPDF is versatile, offering functionality that not only renders PDFs but also provides a wide range of PDF manipulation options like editing, form handling, encryption, and more.

Key Features of IronPDF

HTML to PDF Conversion
- HTML Rendering: IronPDF can convert HTML file format documents or web pages (including HTML with CSS, images, and JavaScript) directly into a PDF document. It can also convert using HTML template. This is ideal for generating PDFs from dynamic web content.
- Support for Modern HTML/CSS: IronPDF handles modern HTML5, CSS3, and JavaScript, ensuring that your web-based content is rendered accurately as a PDF, preserving the layout, fonts, and interactive elements.
- Advanced Rendering: It uses Chrome’s rendering engine (via Chromium) for accurate, high-quality PDF generation, making it more reliable than many other HTML-to-PDF libraries.
- Website Url to PDF: IronPDF can take string url of the website as input and convert to PDF.
Custom Headers and Footers
- IronPDF allows developers to add custom headers and footers to PDF documents, which can include dynamic content such as page numbers, document title, or custom text.
- Headers and footers can be added to individual pages, or as consistent elements across the entire document.
Support for JavaScript in PDFs
- IronPDF enables JavaScript execution within the HTML content before PDF generation. This allows for dynamic content rendering, such as form calculations or interactivity in the generated PDFs.
- JavaScript is useful when creating PDFs from dynamic web pages or generating reports that require client-side logic.
Edit Existing PDFs
- IronPDF provides the ability to edit existing PDFs. You can modify text, images, and add annotations to existing PDF files. This feature is useful for watermarking documents, adding signatures, or updating content within PDF files.
- Text extraction and modification allow you to manipulate content within a PDF document programmatically.
Merge and Split PDFs
- IronPDF allows you to merge multiple PDF files into a single document or split a large PDF into smaller files. This is ideal for workflows where documents need to be combined or broken down into more manageable parts.
Support for Interactive Forms
- You can create, fill, and manipulate PDF forms using IronPDF. It provides full support for interactive forms (like text fields, checkboxes, and radio buttons) and allows you to pre-fill forms with data.
- IronPDF also allows for extracting form data from existing PDFs, making it easy to read and process the form data programmatically.
Page Manipulation
- IronPDF offers various methods for manipulating individual pages within a PDF document, such as rotating pages, deleting pages, or reordering them. This helps in customizing the structure of the final document.
- You can also add new pages to an existing PDF, or remove unwanted pages.
Security and Encryption
- IronPDF allows you to apply password protection and encryption to PDFs, ensuring that your documents are secure. You can set user permissions, such as preventing printing, copying, or editing the PDF.
- Digital signatures can also be added to PDFs to verify authenticity, providing a layer of security for sensitive documents.
Watermarking and Branding
- Adding watermarks to PDF documents is easy with IronPDF. You can overlay text or images as watermarks onto pages, providing protection against unauthorized copying or distributing of your documents.
- This feature is often used for branding, where the logo or text needs to appear consistently across all pages of a document.
1. Text and Image Extraction
  - IronPDF allows for text and image extraction from PDF documents, enabling developers to extract data for processing or reuse.
- This is helpful for scenarios where you need to analyze the contents of a PDF, extract information from forms, or retrieve images for further use.
1. Unicode and Multi-language Support
  - IronPDF has robust Unicode support, meaning it can handle international characters and fonts, making it ideal for generating PDFs in multiple languages.
- It supports languages such as Chinese, Arabic, Russian, and more, allowing for the creation of multilingual PDF documents.
1. Optimized for Performance
- IronPDF is optimized for performance, capable of handling large PDF documents and high volumes of requests. The library ensures that even when working with large datasets or images, PDF generation remains fast and efficient.
1. API and Developer-Friendly Tools
  - IronPDF comes with a comprehensive and easy-to-use API. Developers can quickly get started by using simple method calls to perform complex tasks.
- The API is well-documented, making it easy to integrate IronPDF into any C# or .NET application.
1. Cross-Platform Support
- IronPDF is cross-platform compatible, meaning it can be used on both Windows and Linux environments, allowing you to generate and manipulate PDFs across different operating systems.

How to convert HTML to PDF using IronPDF

class Program
{
    static void Main()
    {
        // Specify license key
        License.LicenseKey = "Yoour Key";
        // Create a new HtmlToPdf object
        var Renderer = new ChromePdfRenderer();
        // Define the HTML string/ HTML code to be converted, can use html document
        string htmlContent = "<html><body><h1>IronPDF: Easily Convert HTML to PDF</h1></body></html>";
        // Convert pdf simple HTML string to a PDF document
        var document = Renderer.RenderHtmlAsPdf(htmlContent);
        // Save the PDF output document to a file
        document.SaveAs("html2Pdf.pdf"); // path to pdf file generated
    }
}

class Program
{
    static void Main()
    {
        // Specify license key
        License.LicenseKey = "Yoour Key";
        // Create a new HtmlToPdf object
        var Renderer = new ChromePdfRenderer();
        // Define the HTML string/ HTML code to be converted, can use html document
        string htmlContent = "<html><body><h1>IronPDF: Easily Convert HTML to PDF</h1></body></html>";
        // Convert pdf simple HTML string to a PDF document
        var document = Renderer.RenderHtmlAsPdf(htmlContent);
        // Save the PDF output document to a file
        document.SaveAs("html2Pdf.pdf"); // path to pdf file generated
    }
}

Friend Class Program
	Shared Sub Main()
		' Specify license key
		License.LicenseKey = "Yoour Key"
		' Create a new HtmlToPdf object
		Dim Renderer = New ChromePdfRenderer()
		' Define the HTML string/ HTML code to be converted, can use html document
		Dim htmlContent As String = "<html><body><h1>IronPDF: Easily Convert HTML to PDF</h1></body></html>"
		' Convert pdf simple HTML string to a PDF document
		Dim document = Renderer.RenderHtmlAsPdf(htmlContent)
		' Save the PDF output document to a file
		document.SaveAs("html2Pdf.pdf") ' path to pdf file generated
	End Sub
End Class

Code Snippet Explanation

1. License Key Setup

The program starts by setting the IronPDF license key, which is required to unlock the full functionality of the library.

2. Creating the Renderer

An instance of ChromePdfRenderer is initialized. This component is responsible for converting HTML content into a PDF document, acting as a bridge between the raw HTML and the final output.

3. Defining HTML Content

A string variable, htmlContent, is created to store the HTML structure that will be converted into a PDF. In this example, it contains a simple heading.

4. Converting HTML to PDF

The RenderHtmlAsPdf() method is called on the ChromePdfRenderer instance, passing the HTML string as input. This function processes the content and transforms it into a PDF document.

5. Saving the PDF

Finally, the generated PDF is saved to a file named "html2Pdf.pdf" using the SaveAs() method, storing it on the disk for future access.

Output

How to Convert HTML to PDF C# Without Library: Figure 3 Add from PixabayUpload

or drag and drop an image here

Add image alt text

License Information (Trial Available)

IronPDF requires a valid license key for full functionality. You can obtain a trial license from the official website. Before using the IronPDF library, set the license key as follows:

IronPdf.License.LicenseKey = "your key";

IronPdf.License.LicenseKey = "your key";

IronPdf.License.LicenseKey = "your key"

This ensures that the library operates without limitations.

Conclusion

While using built-in .NET features for HTML to PDF conversion might be a feasible solution for simple use cases, it often requires significant effort and lacks modern capabilities. In contrast, libraries like IronPDF offer robust functionality, faster development, and support for advanced HTML rendering, making them the go-to choice for most developers. The decision ultimately depends on your project requirements, budget, and development priorities.

Chipego Kalinda

Chat with engineering team now

Software Engineer

Chipego has a natural skill for listening that helps him to comprehend customer issues, and offer intelligent solutions. He joined the Iron Software team in 2023, after studying a Bachelor of Science in Information Technology. IronPDF and IronOCR are the two products Chipego has been focusing on, but his knowledge of all products is growing daily, as he finds new ways to support customers. He enjoys how collaborative life is at Iron Software, with team members from across the company bringing their varied experience to contribute to effective, innovative solutions. When Chipego is away from his desk, he can often be found enjoying a good book or playing football.

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