PdfiumViewer vs IronPDF: Technical Comparison Guide

What Is PdfiumViewer?

PdfiumViewer is a .NET wrapper for PDFium, Google's PDF rendering engine used within the Chrome browser. The library provides high-performance PDF rendering specifically designed for Windows Forms applications, offering a PdfViewer control that can be embedded directly into WinForms interfaces.

Distributed under the Apache 2.0 license, PdfiumViewer provides cost-effective PDF viewing capabilities. However, its scope is fundamentally limited to viewing and rendering—the library cannot create, edit, or manipulate PDF documents. Additionally, PdfiumViewer faces uncertain maintenance status, which creates risk for production applications requiring long-term support.

Key characteristics of PdfiumViewer include:

• Viewing-Only Focus: Designed specifically for displaying PDF content
• Windows Forms Specific: Restricted to WinForms applications
• Open Source: Apache 2.0 license with no licensing costs
• Native Binary Dependencies: Requires platform-specific PDFium binaries (x86/x64)
• Uncertain Maintenance: Limited updates and unclear long-term support

What Is IronPDF?

IronPDF is a complete .NET library providing full PDF lifecycle management. The ChromePdfRenderer class uses a modern Chromium-based engine to create PDFs from HTML, CSS, and JavaScript, while the PdfDocument class offers extensive manipulation and extraction capabilities.

Unlike PdfiumViewer's viewing-only focus, IronPDF handles PDF creation, text extraction, manipulation, merging, watermarking, and security—all within a single library. The library works across Console, Web, and Desktop applications, extending well beyond Windows Forms limitations.

Architectural Comparison

The fundamental difference between PdfiumViewer and IronPDF lies in their scope: viewing-only versus complete PDF solution.

For applications requiring only PDF viewing in Windows Forms, PdfiumViewer may suffice. For applications needing PDF generation, text extraction, or any creation capabilities, IronPDF provides a complete solution.

HTML to PDF Conversion

HTML-to-PDF conversion demonstrates the fundamental capability gap between these libraries.

PdfiumViewer HTML-to-PDF approach:

// NuGet: Install-Package PdfiumViewer
using PdfiumViewer;
using System.IO;
using System.Drawing.Printing;

// PDFiumViewer is primarily a PDF viewer/renderer, not a generator
// It cannot directly convert HTML to PDF
// You would need to use another library to first create the PDF
// Then use PDFiumViewer to display it:

string htmlContent = "<h1>Hello World</h1><p>This is a test document.</p>";

// This functionality is NOT available in PDFiumViewer
// You would need a different library like wkhtmltopdf or similar
// PDFiumViewer can only open and display existing PDFs:

string existingPdfPath = "output.pdf";
using (var document = PdfDocument.Load(existingPdfPath))
{
    // Can only render/display existing PDF
    var image = document.Render(0, 300, 300, true);
}

// NuGet: Install-Package PdfiumViewer
using PdfiumViewer;
using System.IO;
using System.Drawing.Printing;

// PDFiumViewer is primarily a PDF viewer/renderer, not a generator
// It cannot directly convert HTML to PDF
// You would need to use another library to first create the PDF
// Then use PDFiumViewer to display it:

string htmlContent = "<h1>Hello World</h1><p>This is a test document.</p>";

// This functionality is NOT available in PDFiumViewer
// You would need a different library like wkhtmltopdf or similar
// PDFiumViewer can only open and display existing PDFs:

string existingPdfPath = "output.pdf";
using (var document = PdfDocument.Load(existingPdfPath))
{
    // Can only render/display existing PDF
    var image = document.Render(0, 300, 300, true);
}

IronPDF HTML-to-PDF approach:

// NuGet: Install-Package IronPdf
using IronPdf;
using System;

string htmlContent = "<h1>Hello World</h1><p>This is a test document.</p>";

// Create a PDF from HTML string
var renderer = new ChromePdfRenderer();
PdfDocument pdf = renderer.RenderHtmlAsPdf(htmlContent);

// Save the PDF
pdf.SaveAs("output.pdf");

Console.WriteLine("PDF created successfully!");

// NuGet: Install-Package IronPdf
using IronPdf;
using System;

string htmlContent = "<h1>Hello World</h1><p>This is a test document.</p>";

// Create a PDF from HTML string
var renderer = new ChromePdfRenderer();
PdfDocument pdf = renderer.RenderHtmlAsPdf(htmlContent);

// Save the PDF
pdf.SaveAs("output.pdf");

Console.WriteLine("PDF created successfully!");

PdfiumViewer cannot create PDFs from HTML—it simply doesn't support this functionality. The library can only open and display existing PDF files. Applications requiring HTML to PDF conversion would need to combine PdfiumViewer with additional libraries, creating complexity and potential compatibility issues.

IronPDF's ChromePdfRenderer uses a modern Chromium engine to convert HTML content with full support for CSS3, Flexbox, Grid, and JavaScript execution, producing high-fidelity PDF output from web content.

Text Extraction

Text extraction demonstrates another significant capability gap between these libraries.

PdfiumViewer text extraction approach:

// NuGet: Install-Package PdfiumViewer
using PdfiumViewer;
using System;
using System.Text;

string pdfPath = "document.pdf";

// PDFiumViewer has limited text extraction capabilities
// It's primarily designed for rendering, not text extraction
using (var document = PdfDocument.Load(pdfPath))
{
    int pageCount = document.PageCount;
    Console.WriteLine($"Total pages: {pageCount}");

    // PDFiumViewer does not have built-in text extraction
    // You would need to use OCR or another library
    // It can only render pages as images
    for (int i = 0; i < pageCount; i++)
    {
        var pageImage = document.Render(i, 96, 96, false);
        Console.WriteLine($"Rendered page {i + 1}");
    }
}

// NuGet: Install-Package PdfiumViewer
using PdfiumViewer;
using System;
using System.Text;

string pdfPath = "document.pdf";

// PDFiumViewer has limited text extraction capabilities
// It's primarily designed for rendering, not text extraction
using (var document = PdfDocument.Load(pdfPath))
{
    int pageCount = document.PageCount;
    Console.WriteLine($"Total pages: {pageCount}");

    // PDFiumViewer does not have built-in text extraction
    // You would need to use OCR or another library
    // It can only render pages as images
    for (int i = 0; i < pageCount; i++)
    {
        var pageImage = document.Render(i, 96, 96, false);
        Console.WriteLine($"Rendered page {i + 1}");
    }
}

IronPDF text extraction approach:

// NuGet: Install-Package IronPdf
using IronPdf;
using System;

string pdfPath = "document.pdf";

// Open and extract text from PDF
PdfDocument pdf = PdfDocument.FromFile(pdfPath);

// Extract text from all pages
string allText = pdf.ExtractAllText();
Console.WriteLine("Extracted Text:");
Console.WriteLine(allText);

// Extract text from specific page
string pageText = pdf.ExtractTextFromPage(0);
Console.WriteLine($"\nFirst page text: {pageText}");

Console.WriteLine($"\nTotal pages: {pdf.PageCount}");

// NuGet: Install-Package IronPdf
using IronPdf;
using System;

string pdfPath = "document.pdf";

// Open and extract text from PDF
PdfDocument pdf = PdfDocument.FromFile(pdfPath);

// Extract text from all pages
string allText = pdf.ExtractAllText();
Console.WriteLine("Extracted Text:");
Console.WriteLine(allText);

// Extract text from specific page
string pageText = pdf.ExtractTextFromPage(0);
Console.WriteLine($"\nFirst page text: {pageText}");

Console.WriteLine($"\nTotal pages: {pdf.PageCount}");

PdfiumViewer is primarily designed for rendering, not text extraction. The documentation explicitly notes that it "does not have built-in text extraction" and that you would need to use OCR or another library. The library can only render pages as images.

IronPDF's ExtractAllText() method extracts all text from all pages in a single call. For more granular control, ExtractTextFromPage() provides text from specific pages. This native text extraction capability eliminates the need for OCR or additional libraries.

PDF to Image Conversion

PDF-to-image rendering is one area where PdfiumViewer excels—this is its primary strength as a rendering engine.

PdfiumViewer PDF-to-image approach:

// NuGet: Install-Package PdfiumViewer
using PdfiumViewer;
using System;
using System.Drawing;
using System.Drawing.Imaging;

string pdfPath = "document.pdf";
string outputImage = "page1.png";

// PDFiumViewer excels at rendering PDFs to images
using (var document = PdfDocument.Load(pdfPath))
{
    // Render first page at 300 DPI
    int dpi = 300;
    using (var image = document.Render(0, dpi, dpi, true))
    {
        // Save as PNG
        image.Save(outputImage, ImageFormat.Png);
        Console.WriteLine($"Page rendered to {outputImage}");
    }

    // Render all pages
    for (int i = 0; i < document.PageCount; i++)
    {
        using (var pageImage = document.Render(i, 150, 150, true))
        {
            pageImage.Save($"page_{i + 1}.png", ImageFormat.Png);
        }
    }
}

// NuGet: Install-Package PdfiumViewer
using PdfiumViewer;
using System;
using System.Drawing;
using System.Drawing.Imaging;

string pdfPath = "document.pdf";
string outputImage = "page1.png";

// PDFiumViewer excels at rendering PDFs to images
using (var document = PdfDocument.Load(pdfPath))
{
    // Render first page at 300 DPI
    int dpi = 300;
    using (var image = document.Render(0, dpi, dpi, true))
    {
        // Save as PNG
        image.Save(outputImage, ImageFormat.Png);
        Console.WriteLine($"Page rendered to {outputImage}");
    }

    // Render all pages
    for (int i = 0; i < document.PageCount; i++)
    {
        using (var pageImage = document.Render(i, 150, 150, true))
        {
            pageImage.Save($"page_{i + 1}.png", ImageFormat.Png);
        }
    }
}

IronPDF PDF-to-image approach:

// NuGet: Install-Package IronPdf
using IronPdf;
using System;
using System.Linq;

string pdfPath = "document.pdf";
string outputImage = "page1.png";

// Open PDF and convert to images
PdfDocument pdf = PdfDocument.FromFile(pdfPath);

// Convert first page to image
var firstPageImage = pdf.ToBitmap(0);
firstPageImage[0].Save(outputImage);
Console.WriteLine($"Page rendered to {outputImage}");

// Convert all pages to images
var allPageImages = pdf.ToBitmap();
for (int i = 0; i < allPageImages.Length; i++)
{
    allPageImages[i].Save($"page_{i + 1}.png");
    Console.WriteLine($"Saved page {i + 1}");
}

Console.WriteLine($"Total pages converted: {pdf.PageCount}");

// NuGet: Install-Package IronPdf
using IronPdf;
using System;
using System.Linq;

string pdfPath = "document.pdf";
string outputImage = "page1.png";

// Open PDF and convert to images
PdfDocument pdf = PdfDocument.FromFile(pdfPath);

// Convert first page to image
var firstPageImage = pdf.ToBitmap(0);
firstPageImage[0].Save(outputImage);
Console.WriteLine($"Page rendered to {outputImage}");

// Convert all pages to images
var allPageImages = pdf.ToBitmap();
for (int i = 0; i < allPageImages.Length; i++)
{
    allPageImages[i].Save($"page_{i + 1}.png");
    Console.WriteLine($"Saved page {i + 1}");
}

Console.WriteLine($"Total pages converted: {pdf.PageCount}");

PdfiumViewer's Render() method provides DPI-based rendering with fine control over output quality. The method requires manual disposal patterns with nested using statements.

IronPDF's ToBitmap() method provides a simpler API, returning bitmap arrays that can be saved or processed. Both libraries handle this task effectively, though with different API patterns.

API Mapping Reference

For teams considering PdfiumViewer migration to IronPDF, understanding the API mappings helps estimate effort.

Native Binary Dependencies

A significant architectural difference lies in dependency management.

PdfiumViewer deployment structure:

MyApp/
├── bin/
│   ├── MyApp.dll
│   ├── PdfiumViewer.dll
│   ├── x86/
│   │   └── pdfium.dll
│   └── x64/
│       └── pdfium.dll

IronPDF deployment structure:

MyApp/
├── bin/
│   ├── MyApp.dll
│   └── IronPdf.dll  # Everything included

PdfiumViewer requires bundling and managing platform-specific native binaries. This creates deployment complexity, especially for applications targeting multiple platforms. Each target environment needs the correct native DLL, and the application must correctly load the appropriate version at runtime.

IronPDF's fully managed architecture eliminates these concerns. The library handles its dependencies internally, simplifying deployment.

Feature Comparison Summary

The scope difference between PdfiumViewer and IronPDF spans virtually every PDF operation beyond basic viewing.

Applications requiring text extraction, PDF merging, or watermarking cannot achieve these with PdfiumViewer alone.

Built-in Viewer Considerations

One area where PdfiumViewer has an advantage is its built-in PdfViewer control for Windows Forms applications. IronPDF is backend-focused and does not include a viewer control.

For applications migrating from PdfiumViewer that require PDF viewing, alternatives include:

• Default System Viewer: Use Process.Start() to open PDFs in the user's default PDF application
• WebBrowser Control: Display PDFs in a WinForms WebBrowser control (requires PDF plugin)
• Third-Party Viewers: Specialized viewer controls from vendors like Syncfusion, DevExpress, or Telerik
• Web-Based Viewing: For web applications, serve the PDF and let the browser display it

// Open in default PDF viewer
Process.Start(new ProcessStartInfo(pdfPath) { UseShellExecute = true });

// Open in default PDF viewer
Process.Start(new ProcessStartInfo(pdfPath) { UseShellExecute = true });

When Teams Consider Moving from PdfiumViewer to IronPDF

Several factors drive teams to evaluate IronPDF as an alternative to PdfiumViewer:

PDF Creation Requirements: PdfiumViewer cannot create PDFs. Applications needing to generate PDFs from HTML templates, reports, or web content require additional libraries. IronPDF provides complete PDF creation with a modern Chromium engine.

Text Extraction Needs: PdfiumViewer cannot extract text from PDFs—it can only render pages as images. Applications requiring text search, indexing, or content analysis need IronPDF's native text extraction capabilities.

Platform Expansion: PdfiumViewer is restricted to Windows Forms applications. Organizations building ASP.NET web applications, Console utilities, or cross-platform solutions need IronPDF's broader platform support.

Maintenance Concerns: PdfiumViewer's uncertain maintenance status creates risk for production applications requiring long-term support. IronPDF provides active development and professional support.

Feature Expansion: As applications mature, requirements often expand beyond viewing to include document merging, watermarking, or security settings. IronPDF provides these capabilities natively.

Installation Comparison

PdfiumViewer installation:

Install-Package PdfiumViewer
Install-Package PdfiumViewer.Native.x86.v8-xfa
Install-Package PdfiumViewer.Native.x64.v8-xfa

Install-Package PdfiumViewer
Install-Package PdfiumViewer.Native.x86.v8-xfa
Install-Package PdfiumViewer.Native.x64.v8-xfa

Plus native binary management.

IronPDF installation:

Install-Package IronPdf

Install-Package IronPdf

IronPDF requires a license key configuration at application startup:

IronPdf.License.LicenseKey = "YOUR-LICENSE-KEY";

IronPdf.License.LicenseKey = "YOUR-LICENSE-KEY";

Both libraries support .NET Framework, with IronPDF also supporting .NET Core, .NET 5+, and beyond into .NET 10 and C# 14.

Making the Decision

The choice between PdfiumViewer and IronPDF depends on your application requirements:

Consider PdfiumViewer if: You need only PDF viewing in Windows Forms, don't require PDF creation or text extraction, want a free open-source solution, and are comfortable with uncertain long-term maintenance.

Consider IronPDF if: You need PDF creation from HTML or URLs, require text extraction capabilities, want support beyond Windows Forms, need PDF manipulation (merge, split, watermark), require active maintenance and support, or are building applications with expanding PDF requirements.

For most modern applications, the ability to create, extract, and manipulate PDFs is essential. PdfiumViewer's viewing-only focus makes it insufficient for comprehensive PDF workflows without additional libraries. IronPDF's complete solution eliminates the need for library combinations while providing a unified API for all PDF operations.

Getting Started with IronPDF

To evaluate IronPDF for your PDF needs:

1. Install the IronPDF NuGet package: Install-Package IronPdf
2. Review the HTML to PDF tutorial for creation patterns
3. Explore text extraction capabilities for content processing
4. Check the tutorials section for comprehensive examples

The IronPDF documentation provides detailed guidance for common scenarios, and the API reference documents all available classes and methods.

Conclusion

PdfiumViewer and IronPDF serve fundamentally different purposes in the .NET PDF ecosystem. PdfiumViewer excels at PDF viewing in Windows Forms applications—displaying documents with high fidelity using Google's PDFium engine. IronPDF provides a complete PDF solution covering creation, text extraction, manipulation, and rendering in a single library.

For applications requiring only PDF viewing in Windows Forms, PdfiumViewer's focused approach may be appropriate. For applications needing PDF generation, text extraction, document merging, or any creation capabilities, IronPDF provides these features natively without requiring additional libraries.

The decision extends beyond current requirements to anticipated needs and maintenance considerations. PdfiumViewer's uncertain maintenance status creates project risk, while applications often start with viewing but expand to require creation and manipulation. Choosing IronPDF from the start provides a foundation for these expanded requirements while ensuring long-term support and active development.

Evaluate your complete PDF requirements—current and anticipated—when selecting between these libraries. The viewing-only nature of PdfiumViewer creates architectural limitations that become apparent as applications mature and requirements expand.