MIGRATION GUIDES

How to Migrate from EO.Pdf to IronPDF in C#

Published:January 11, 2026

EO.Pdf presents several architectural challenges that drive development teams to evaluate alternatives. Understanding these issues is essential for planning your migration strategy.

The EO.Pdf Problems

Massive 126MB Package Size: EO.Pdf bundles its own Chromium engine, resulting in a 126MB deployment footprint. This inflates Docker images, slows CI/CD pipelines, and increases infrastructure costs.
Legacy Architecture Baggage: EO.Pdf was originally built on Internet Explorer's rendering engine before migrating to Chromium. This legacy introduces compatibility issues from the IE era, technical debt in the API design, and inconsistent behavior between versions.
Windows-Centric Design: Despite marketing as "cross-platform," EO.Pdf's Linux and macOS support is limited. Many developers report issues with non-Windows deployments.
Static Global Options: EO.Pdf uses static HtmlToPdf.Options for configuration, which is not thread-safe and problematic in multi-tenant web applications.
$799 Per License: At $799 per developer license, EO.Pdf is expensive compared to alternatives offering similar or better functionality.

Architecture Comparison

Aspect	EO.Pdf	IronPDF
Package Size	126MB	Optimized (~50MB)
Legacy Issues	IE migration baggage	Clean, modern codebase
Platform Support	Windows-focused	True cross-platform
Configuration	Static/global (not thread-safe)	Instance-based, thread-safe
API Design	Mixed (HtmlToPdf + ACM)	Unified, consistent
Documentation	Limited	Comprehensive tutorials
Modern .NET	.NET Standard	.NET 6/7/8/9+ native
Async Support	Limited	Full async/await

Key Migration Benefits

50% Smaller Footprint: IronPDF's optimized Chromium packaging
True Cross-Platform: Works identically on Windows, Linux, macOS, Docker
Thread-Safe Configuration: Instance-based renderer options
Modern API: Consistent, intuitive method names
Better Documentation: Extensive tutorials and examples

Pre-Migration Preparation

Prerequisites

Ensure your environment meets these requirements:

.NET Framework 4.6.2+ or .NET Core 3.1 / .NET 5-9
Visual Studio 2019+ or VS Code with C# extension
NuGet Package Manager access
IronPDF license key (free trial available at ironpdf.com)

Audit EO.Pdf Usage

Run these commands in your solution directory to identify all EO.Pdf references:

# Find all EO.Pdf references
grep -r "EO.Pdf\|HtmlToPdf\|AcmRender\|PdfDocument" --include="*.cs" .

# Check NuGet packages
dotnet list package | grep -i "EO.Pdf"

# Find all EO.Pdf references
grep -r "EO.Pdf\|HtmlToPdf\|AcmRender\|PdfDocument" --include="*.cs" .

# Check NuGet packages
dotnet list package | grep -i "EO.Pdf"

SHELL

Common EO.Pdf namespaces to look for:

EO.Pdf - Core HTML to PDF
EO.Pdf.Acm - Advanced Content Model (ACM)
EO.Pdf.Contents - Low-level content manipulation
EO.Pdf.Drawing - Graphics operations

Understanding the Core Pattern Change

The most significant architectural difference between EO.Pdf and IronPDF is configuration scope. EO.Pdf uses static methods with global options that affect all conversions—a pattern that causes thread-safety issues in web applications. IronPDF uses instance-based renderers with local options, ensuring each conversion is isolated.

Step-by-Step Migration Process

Step 1: Update NuGet Packages

Remove EO.Pdf and install IronPDF:

# Remove EO.Pdf
dotnet remove package EO.Pdf

# Install IronPDF
dotnet add package IronPdf

# Remove EO.Pdf
dotnet remove package EO.Pdf

# Install IronPDF
dotnet add package IronPdf

SHELL

Step 2: Update Namespace References

Replace EO.Pdf namespaces with IronPDF:

// Remove these
using EO.Pdf;
using EO.Pdf.Acm;

// Add this
using IronPdf;

// Remove these
using EO.Pdf;
using EO.Pdf.Acm;

// Add this
using IronPdf;

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Step 3: Configure License

// Add at application startup (Program.cs or Startup.cs)
IronPdf.License.LicenseKey = "YOUR-LICENSE-KEY";

// Add at application startup (Program.cs or Startup.cs)
IronPdf.License.LicenseKey = "YOUR-LICENSE-KEY";

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Complete API Migration Reference

Core Class Mapping

EO.Pdf Class	IronPDF Equivalent	Notes
`HtmlToPdf`	`ChromePdfRenderer`	Instance-based
`PdfDocument`	`PdfDocument`	Similar but different methods
`HtmlToPdfOptions`	`ChromePdfRenderOptions`	Via `RenderingOptions`
`AcmRender`	Not needed	Use HTML/CSS instead
`AcmText`	HTML `<span>`, `<p>`
`AcmBlock`	HTML `<div>`

Method Mapping

EO.Pdf Method	IronPDF Method	Notes
`HtmlToPdf.ConvertHtml(html, path)`	`renderer.RenderHtmlAsPdf(html)` then `SaveAs(path)`	Two-step in IronPDF
`HtmlToPdf.ConvertUrl(url, path)`	`renderer.RenderUrlAsPdf(url)` then `SaveAs(path)`
`PdfDocument.Save(path)`	`pdf.SaveAs(path)`
`new PdfDocument(path)`	`PdfDocument.FromFile(path)`	Static factory
`doc.Append(other)`	`PdfDocument.Merge(doc1, doc2)`	Static merge method

Options Mapping

EO.Pdf Option	IronPDF RenderingOptions	Notes
`Options.PageSize = PdfPageSizes.A4`	`PaperSize = PdfPaperSize.A4`
`Options.OutputArea` (RectangleF)	`MarginTop`, `MarginBottom`, etc.	Individual properties in mm

Code Migration Examples

HTML to PDF Conversion

The fundamental HTML to PDF conversion demonstrates the shift from static methods to instance-based rendering.

EO.Pdf Implementation:

// NuGet: Install-Package EO.Pdf
using EO.Pdf;
using System;

class Program
{
    static void Main()
    {
        string html = "<html><body><h1>Hello World</h1><p>This is a PDF generated from HTML.</p></body></html>";

        HtmlToPdf.ConvertHtml(html, "output.pdf");

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

// NuGet: Install-Package EO.Pdf
using EO.Pdf;
using System;

class Program
{
    static void Main()
    {
        string html = "<html><body><h1>Hello World</h1><p>This is a PDF generated from HTML.</p></body></html>";

        HtmlToPdf.ConvertHtml(html, "output.pdf");

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

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IronPDF Implementation:

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

class Program
{
    static void Main()
    {
        string html = "<html><body><h1>Hello World</h1><p>This is a PDF generated from HTML.</p></body></html>";

        var renderer = new ChromePdfRenderer();
        var pdf = renderer.RenderHtmlAsPdf(html);
        pdf.SaveAs("output.pdf");

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

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

class Program
{
    static void Main()
    {
        string html = "<html><body><h1>Hello World</h1><p>This is a PDF generated from HTML.</p></body></html>";

        var renderer = new ChromePdfRenderer();
        var pdf = renderer.RenderHtmlAsPdf(html);
        pdf.SaveAs("output.pdf");

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

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IronPDF's two-step pattern (render, then save) provides access to the PdfDocument object for additional manipulation before saving. For more options, see the HTML to PDF documentation.

URL to PDF Conversion

EO.Pdf Implementation:

// NuGet: Install-Package EO.Pdf
using EO.Pdf;
using System;

class Program
{
    static void Main()
    {
        string url = "https://www.example.com";

        HtmlToPdf.ConvertUrl(url, "webpage.pdf");

        Console.WriteLine("PDF from URL created successfully!");
    }
}

// NuGet: Install-Package EO.Pdf
using EO.Pdf;
using System;

class Program
{
    static void Main()
    {
        string url = "https://www.example.com";

        HtmlToPdf.ConvertUrl(url, "webpage.pdf");

        Console.WriteLine("PDF from URL created successfully!");
    }
}

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IronPDF Implementation:

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

class Program
{
    static void Main()
    {
        string url = "https://www.example.com";

        var renderer = new ChromePdfRenderer();
        var pdf = renderer.RenderUrlAsPdf(url);
        pdf.SaveAs("webpage.pdf");

        Console.WriteLine("PDF from URL created successfully!");
    }
}

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

class Program
{
    static void Main()
    {
        string url = "https://www.example.com";

        var renderer = new ChromePdfRenderer();
        var pdf = renderer.RenderUrlAsPdf(url);
        pdf.SaveAs("webpage.pdf");

        Console.WriteLine("PDF from URL created successfully!");
    }
}

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IronPDF's RenderUrlAsPdf provides full JavaScript execution and modern CSS support. For more options, see the URL to PDF documentation.

HTML File with Custom Settings

This example demonstrates the critical difference in configuration patterns—EO.Pdf's OutputArea with inches versus IronPDF's individual margin properties in millimeters.

EO.Pdf Implementation:

// NuGet: Install-Package EO.Pdf
using EO.Pdf;
using System;

class Program
{
    static void Main()
    {
        HtmlToPdfOptions options = new HtmlToPdfOptions();
        options.PageSize = PdfPageSizes.A4;
        options.OutputArea = new RectangleF(0.5f, 0.5f, 7.5f, 10.5f);

        HtmlToPdf.ConvertUrl("file:///C:/input.html", "output.pdf", options);
        Console.WriteLine("PDF with custom settings created.");
    }
}

// NuGet: Install-Package EO.Pdf
using EO.Pdf;
using System;

class Program
{
    static void Main()
    {
        HtmlToPdfOptions options = new HtmlToPdfOptions();
        options.PageSize = PdfPageSizes.A4;
        options.OutputArea = new RectangleF(0.5f, 0.5f, 7.5f, 10.5f);

        HtmlToPdf.ConvertUrl("file:///C:/input.html", "output.pdf", options);
        Console.WriteLine("PDF with custom settings created.");
    }
}

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IronPDF Implementation:

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

class Program
{
    static void Main()
    {
        var renderer = new ChromePdfRenderer();
        renderer.RenderingOptions.PaperSize = PdfPaperSize.A4;
        renderer.RenderingOptions.MarginTop = 20;
        renderer.RenderingOptions.MarginBottom = 20;
        renderer.RenderingOptions.MarginLeft = 20;
        renderer.RenderingOptions.MarginRight = 20;

        var pdf = renderer.RenderHtmlFileAsPdf("C:/input.html");
        pdf.SaveAs("output.pdf");
        Console.WriteLine("PDF with custom settings created.");
    }
}

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

class Program
{
    static void Main()
    {
        var renderer = new ChromePdfRenderer();
        renderer.RenderingOptions.PaperSize = PdfPaperSize.A4;
        renderer.RenderingOptions.MarginTop = 20;
        renderer.RenderingOptions.MarginBottom = 20;
        renderer.RenderingOptions.MarginLeft = 20;
        renderer.RenderingOptions.MarginRight = 20;

        var pdf = renderer.RenderHtmlFileAsPdf("C:/input.html");
        pdf.SaveAs("output.pdf");
        Console.WriteLine("PDF with custom settings created.");
    }
}

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Note the unit conversion: EO.Pdf uses inches in OutputArea, while IronPDF uses millimeters. Convert using: inches × 25.4 = mm. For more options, see the rendering options documentation.

Merging Multiple PDFs

PDF merging demonstrates the difference between EO.Pdf's Append loop pattern and IronPDF's static Merge method.

EO.Pdf Implementation:

// NuGet: Install-Package EO.Pdf
using EO.Pdf;
using System;

class Program
{
    static void Main()
    {
        PdfDocument doc1 = new PdfDocument("file1.pdf");
        PdfDocument doc2 = new PdfDocument("file2.pdf");

        PdfDocument mergedDoc = new PdfDocument();
        mergedDoc.Append(doc1);
        mergedDoc.Append(doc2);

        mergedDoc.Save("merged.pdf");

        Console.WriteLine("PDFs merged successfully!");
    }
}

// NuGet: Install-Package EO.Pdf
using EO.Pdf;
using System;

class Program
{
    static void Main()
    {
        PdfDocument doc1 = new PdfDocument("file1.pdf");
        PdfDocument doc2 = new PdfDocument("file2.pdf");

        PdfDocument mergedDoc = new PdfDocument();
        mergedDoc.Append(doc1);
        mergedDoc.Append(doc2);

        mergedDoc.Save("merged.pdf");

        Console.WriteLine("PDFs merged successfully!");
    }
}

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IronPDF Implementation:

// NuGet: Install-Package IronPdf
using IronPdf;
using System;
using System.Collections.Generic;

class Program
{
    static void Main()
    {
        var pdf1 = PdfDocument.FromFile("file1.pdf");
        var pdf2 = PdfDocument.FromFile("file2.pdf");

        var merged = PdfDocument.Merge(new List<PdfDocument> { pdf1, pdf2 });
        merged.SaveAs("merged.pdf");

        Console.WriteLine("PDFs merged successfully!");
    }
}

// NuGet: Install-Package IronPdf
using IronPdf;
using System;
using System.Collections.Generic;

class Program
{
    static void Main()
    {
        var pdf1 = PdfDocument.FromFile("file1.pdf");
        var pdf2 = PdfDocument.FromFile("file2.pdf");

        var merged = PdfDocument.Merge(new List<PdfDocument> { pdf1, pdf2 });
        merged.SaveAs("merged.pdf");

        Console.WriteLine("PDFs merged successfully!");
    }
}

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IronPDF's static Merge method accepts a collection of documents, simplifying multi-document merging. Note the change from constructor (new PdfDocument(path)) to static factory (PdfDocument.FromFile(path)). For more options, see the PDF merging documentation.

Critical Migration Notes

Margin Unit Conversion

EO.Pdf uses inches in OutputArea. IronPDF uses millimeters. Convert using: inches × 25.4 = mm

// EO.Pdf - 0.5 inch margins
options.OutputArea = new RectangleF(0.5f, 0.5f, 7.5f, 10.5f);

// IronPDF - equivalent in millimeters (0.5" = 12.7mm)
renderer.RenderingOptions.MarginTop = 12.7;
renderer.RenderingOptions.MarginBottom = 12.7;
renderer.RenderingOptions.MarginLeft = 12.7;
renderer.RenderingOptions.MarginRight = 12.7;

// EO.Pdf - 0.5 inch margins
options.OutputArea = new RectangleF(0.5f, 0.5f, 7.5f, 10.5f);

// IronPDF - equivalent in millimeters (0.5" = 12.7mm)
renderer.RenderingOptions.MarginTop = 12.7;
renderer.RenderingOptions.MarginBottom = 12.7;
renderer.RenderingOptions.MarginLeft = 12.7;
renderer.RenderingOptions.MarginRight = 12.7;

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Static to Instance-Based Configuration

Replace all HtmlToPdf.Options.X with renderer.RenderingOptions.X:

// EO.Pdf - static options (NOT thread-safe!)
HtmlToPdf.Options.PageSize = PdfPageSizes.A4;

// IronPDF - instance options (thread-safe)
var renderer = new ChromePdfRenderer();
renderer.RenderingOptions.PaperSize = PdfPaperSize.A4;

// EO.Pdf - static options (NOT thread-safe!)
HtmlToPdf.Options.PageSize = PdfPageSizes.A4;

// IronPDF - instance options (thread-safe)
var renderer = new ChromePdfRenderer();
renderer.RenderingOptions.PaperSize = PdfPaperSize.A4;

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ACM to HTML Migration

If using EO.Pdf's Advanced Content Model (AcmRender, AcmText, AcmBlock), migrate to standard HTML/CSS:

// EO.Pdf ACM approach
var acmContent = new AcmContent();
acmContent.Add(new AcmText("Sample Text"));

// IronPDF HTML approach
var html = "<div>Sample Text</div>";
var renderer = new ChromePdfRenderer();
var pdf = renderer.RenderHtmlAsPdf(html);

// EO.Pdf ACM approach
var acmContent = new AcmContent();
acmContent.Add(new AcmText("Sample Text"));

// IronPDF HTML approach
var html = "<div>Sample Text</div>";
var renderer = new ChromePdfRenderer();
var pdf = renderer.RenderHtmlAsPdf(html);

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Two-Step Save Pattern

EO.Pdf saves directly in ConvertHtml(). IronPDF returns a PdfDocument object, then you call SaveAs():

// EO.Pdf - one step
HtmlToPdf.ConvertHtml(html, "output.pdf");

// IronPDF - two steps (enables manipulation before save)
var pdf = renderer.RenderHtmlAsPdf(html);
pdf.SaveAs("output.pdf");

// EO.Pdf - one step
HtmlToPdf.ConvertHtml(html, "output.pdf");

// IronPDF - two steps (enables manipulation before save)
var pdf = renderer.RenderHtmlAsPdf(html);
pdf.SaveAs("output.pdf");

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Constructor to Static Factory

Replace new PdfDocument(path) with PdfDocument.FromFile(path):

// EO.Pdf
var doc = new PdfDocument("file.pdf");

// IronPDF
var doc = PdfDocument.FromFile("file.pdf");

// EO.Pdf
var doc = new PdfDocument("file.pdf");

// IronPDF
var doc = PdfDocument.FromFile("file.pdf");

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Post-Migration Checklist

After completing the code migration, verify the following:

Visual comparison of generated PDFs
Verify headers/footers render correctly
Test security/encryption settings
Validate merging operations
Performance benchmarking
Cross-platform testing (Windows, Linux, macOS)
Remove EO.Pdf license files
Update documentation

Future-Proofing Your PDF Infrastructure

With .NET 10 on the horizon and C# 14 introducing new language features, choosing a PDF library with modern .NET native support ensures long-term compatibility. IronPDF's instance-based, thread-safe architecture aligns with contemporary web application patterns—particularly important for multi-tenant SaaS applications where EO.Pdf's static global options create concurrency issues.

Additional Resources

Migrating from EO.Pdf to IronPDF eliminates the 126MB package bloat, legacy IE-era baggage, and thread-safety concerns from static global options. The transition to instance-based configuration ensures your PDF generation code works reliably in multi-threaded web applications while providing true cross-platform deployment support.

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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How to Migrate from EO.Pdf to IronPDF in C#

The EO.Pdf Problems

Architecture Comparison

Key Migration Benefits

Pre-Migration Preparation

Prerequisites

Audit EO.Pdf Usage

Understanding the Core Pattern Change

Step-by-Step Migration Process

Step 1: Update NuGet Packages

Step 2: Update Namespace References

Step 3: Configure License

Complete API Migration Reference

Core Class Mapping

Method Mapping

Options Mapping

Code Migration Examples

HTML to PDF Conversion

URL to PDF Conversion

HTML File with Custom Settings

Merging Multiple PDFs

Critical Migration Notes

Margin Unit Conversion

Static to Instance-Based Configuration

ACM to HTML Migration

Two-Step Save Pattern

Constructor to Static Factory

Post-Migration Checklist

Future-Proofing Your PDF Infrastructure

Additional Resources

How to Migrate from EO.Pdf to IronPDF in C#

The EO.Pdf Problems

Architecture Comparison

Key Migration Benefits

Pre-Migration Preparation

Prerequisites

Audit EO.Pdf Usage

Understanding the Core Pattern Change

Step-by-Step Migration Process

Step 1: Update NuGet Packages

Step 2: Update Namespace References

Step 3: Configure License

Complete API Migration Reference

Core Class Mapping

Method Mapping

Options Mapping

Code Migration Examples

HTML to PDF Conversion

URL to PDF Conversion

HTML File with Custom Settings

Merging Multiple PDFs

Critical Migration Notes

Margin Unit Conversion

Static to Instance-Based Configuration

ACM to HTML Migration

Two-Step Save Pattern

Constructor to Static Factory

Post-Migration Checklist

Future-Proofing Your PDF Infrastructure

Additional Resources

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