How to Migrate from ExpertPdf to IronPDF in C#

The ExpertPdf Problems

1. Documentation Frozen Since 2018: ExpertPdf's documentation hasn't been updated in over 6 years. Finding current information, examples, and best practices is increasingly difficult as the .NET ecosystem evolves.

2. Outdated Chrome Version: ExpertPdf relies on a legacy version of Chrome for rendering. Modern CSS3 features (Flexbox, Grid, CSS Variables) may not render correctly, and security patches are not applied.

3. Premium Pricing for Legacy Tech: At $550-$1,200 per license, ExpertPdf charges premium prices while delivering outdated rendering technology.

4. Fragmented Product Suite: ExpertPdf sells separate packages for different functions—HtmlToPdf Converter, PDF Merger, PDF Security, PDF Splitter, and PDF to Image—each requiring separate licensing.

5. Limited Modern .NET Support: While ExpertPdf has .NET Core packages, they lag behind modern .NET versions and practices.

Architecture Comparison

Key Migration Benefits

1. Modern Rendering: Latest Chromium engine for pixel-perfect output
2. All-in-One Package: PDF generation, merging, security, extraction in one NuGet
3. Active Development: Monthly updates with new features and security patches
4. Better Documentation: Comprehensive tutorials and examples
5. True Cross-Platform: Windows, Linux, macOS, Docker support

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 ExpertPdf Usage

Run these commands in your solution directory to identify all ExpertPdf references:

# Find all ExpertPdf references
grep -r "ExpertPdf\|PdfConverter\|PDFMerge\|PdfSecurityManager" --include="*.cs" .

# Check NuGet packages
dotnet list package | grep -i "ExpertPdf"

# Find all ExpertPdf references
grep -r "ExpertPdf\|PdfConverter\|PDFMerge\|PdfSecurityManager" --include="*.cs" .

# Check NuGet packages
dotnet list package | grep -i "ExpertPdf"

Common ExpertPdf packages to look for:

• ExpertPdf.HtmlToPdf - HTML to PDF conversion
• ExpertPdf.PDFMerge - PDF merging
• ExpertPdf.PDFSecurity - Encryption and passwords
• ExpertPdf.PDFSplit - PDF splitting
• ExpertPdf.PdfToImage - PDF to image conversion

Understanding the Core Pattern Change

ExpertPdf uses PdfConverter with direct byte-array return methods. IronPDF uses ChromePdfRenderer returning PdfDocument objects that provide additional manipulation capabilities before saving.

Step 1: Update NuGet Packages

Remove all ExpertPdf packages and install IronPDF:

# Remove all ExpertPdf packages
dotnet remove package ExpertPdf.HtmlToPdf
dotnet remove package ExpertPdf.PDFMerge
dotnet remove package ExpertPdf.PDFSecurity
dotnet remove package ExpertPdf.PDFSplit
dotnet remove package ExpertPdf.PdfToImage

# Install IronPDF (includes all features)
dotnet add package IronPdf

# Remove all ExpertPdf packages
dotnet remove package ExpertPdf.HtmlToPdf
dotnet remove package ExpertPdf.PDFMerge
dotnet remove package ExpertPdf.PDFSecurity
dotnet remove package ExpertPdf.PDFSplit
dotnet remove package ExpertPdf.PdfToImage

# Install IronPDF (includes all features)
dotnet add package IronPdf

Step 2: Update Namespace References

Replace ExpertPdf namespaces with IronPDF:

// Remove these
using ExpertPdf.HtmlToPdf;

// Add this
using IronPdf;

// Remove these
using ExpertPdf.HtmlToPdf;

// Add this
using IronPdf;

Step 3: Configure License

ExpertPdf uses per-converter licensing. IronPDF uses a single global 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";

Core Class Mapping

Method Mapping

Options Mapping

Page Numbering Token Conversion

ExpertPdf and IronPDF use different placeholder syntax for page numbers:

HTML to PDF Conversion

The fundamental HTML to PDF conversion demonstrates the shift from ExpertPdf's byte-array pattern to IronPDF's document-object approach.

ExpertPdf Implementation:

// NuGet: Install-Package ExpertPdf.HtmlToPdf
using ExpertPdf.HtmlToPdf;
using System;

class Program
{
    static void Main()
    {
        // Create the PDF converter
        PdfConverter pdfConverter = new PdfConverter();

        // Convert HTML string to PDF
        byte[] pdfBytes = pdfConverter.GetPdfBytesFromHtmlString("<h1>Hello World</h1><p>This is a PDF document.</p>");

        // Save to file
        System.IO.File.WriteAllBytes("output.pdf", pdfBytes);

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

// NuGet: Install-Package ExpertPdf.HtmlToPdf
using ExpertPdf.HtmlToPdf;
using System;

class Program
{
    static void Main()
    {
        // Create the PDF converter
        PdfConverter pdfConverter = new PdfConverter();

        // Convert HTML string to PDF
        byte[] pdfBytes = pdfConverter.GetPdfBytesFromHtmlString("<h1>Hello World</h1><p>This is a PDF document.</p>");

        // Save to file
        System.IO.File.WriteAllBytes("output.pdf", pdfBytes);

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

IronPDF Implementation:

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

class Program
{
    static void Main()
    {
        // Create a PDF from HTML string
        var renderer = new ChromePdfRenderer();
        var pdf = renderer.RenderHtmlAsPdf("<h1>Hello World</h1><p>This is a PDF document.</p>");

        // Save to file
        pdf.SaveAs("output.pdf");

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

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

class Program
{
    static void Main()
    {
        // Create a PDF from HTML string
        var renderer = new ChromePdfRenderer();
        var pdf = renderer.RenderHtmlAsPdf("<h1>Hello World</h1><p>This is a PDF document.</p>");

        // Save to file
        pdf.SaveAs("output.pdf");

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

IronPDF's approach returns a PdfDocument object, enabling additional manipulation (merging, watermarking, security) before saving. For more options, see the HTML to PDF documentation.

URL to PDF with Page Settings

ExpertPdf Implementation:

// NuGet: Install-Package ExpertPdf.HtmlToPdf
using ExpertPdf.HtmlToPdf;
using System;

class Program
{
    static void Main()
    {
        // Create the PDF converter
        PdfConverter pdfConverter = new PdfConverter();

        // Set page size and orientation
        pdfConverter.PdfDocumentOptions.PdfPageSize = PdfPageSize.A4;
        pdfConverter.PdfDocumentOptions.PdfPageOrientation = PdfPageOrientation.Portrait;

        // Convert URL to PDF
        byte[] pdfBytes = pdfConverter.GetPdfBytesFromUrl("https://www.example.com");

        // Save to file
        System.IO.File.WriteAllBytes("webpage.pdf", pdfBytes);

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

// NuGet: Install-Package ExpertPdf.HtmlToPdf
using ExpertPdf.HtmlToPdf;
using System;

class Program
{
    static void Main()
    {
        // Create the PDF converter
        PdfConverter pdfConverter = new PdfConverter();

        // Set page size and orientation
        pdfConverter.PdfDocumentOptions.PdfPageSize = PdfPageSize.A4;
        pdfConverter.PdfDocumentOptions.PdfPageOrientation = PdfPageOrientation.Portrait;

        // Convert URL to PDF
        byte[] pdfBytes = pdfConverter.GetPdfBytesFromUrl("https://www.example.com");

        // Save to file
        System.IO.File.WriteAllBytes("webpage.pdf", pdfBytes);

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

IronPDF Implementation:

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

class Program
{
    static void Main()
    {
        // Create a PDF renderer
        var renderer = new ChromePdfRenderer();

        // Set page size and orientation
        renderer.RenderingOptions.PaperSize = PdfPaperSize.A4;
        renderer.RenderingOptions.PaperOrientation = PdfPaperOrientation.Portrait;

        // Convert URL to PDF
        var pdf = renderer.RenderUrlAsPdf("https://www.example.com");

        // Save to file
        pdf.SaveAs("webpage.pdf");

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

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

class Program
{
    static void Main()
    {
        // Create a PDF renderer
        var renderer = new ChromePdfRenderer();

        // Set page size and orientation
        renderer.RenderingOptions.PaperSize = PdfPaperSize.A4;
        renderer.RenderingOptions.PaperOrientation = PdfPaperOrientation.Portrait;

        // Convert URL to PDF
        var pdf = renderer.RenderUrlAsPdf("https://www.example.com");

        // Save to file
        pdf.SaveAs("webpage.pdf");

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

IronPDF's RenderingOptions provides direct property access for page configuration. For more options, see the URL to PDF documentation.

Headers and Footers with Page Numbers

This example demonstrates the critical difference in header/footer configuration—ExpertPdf uses separate PdfHeaderOptions and PdfFooterOptions classes with &p;/&P; tokens, while IronPDF uses TextHeaderFooter with {page}/{total-pages} placeholders.

ExpertPdf Implementation:

// NuGet: Install-Package ExpertPdf.HtmlToPdf
using ExpertPdf.HtmlToPdf;
using System;

class Program
{
    static void Main()
    {
        // Create the PDF converter
        PdfConverter pdfConverter = new PdfConverter();

        // Enable header
        pdfConverter.PdfHeaderOptions.ShowHeader = true;
        pdfConverter.PdfHeaderOptions.HeaderText = "Document Header";
        pdfConverter.PdfHeaderOptions.HeaderTextAlignment = HorizontalTextAlign.Center;

        // Enable footer with page numbers
        pdfConverter.PdfFooterOptions.ShowFooter = true;
        pdfConverter.PdfFooterOptions.FooterText = "Page &p; of &P;";
        pdfConverter.PdfFooterOptions.FooterTextAlignment = HorizontalTextAlign.Right;

        // Convert HTML file to PDF
        byte[] pdfBytes = pdfConverter.GetPdfBytesFromHtmlFile("input.html");

        // Save to file
        System.IO.File.WriteAllBytes("output-with-header-footer.pdf", pdfBytes);

        Console.WriteLine("PDF with headers and footers created successfully!");
    }
}

// NuGet: Install-Package ExpertPdf.HtmlToPdf
using ExpertPdf.HtmlToPdf;
using System;

class Program
{
    static void Main()
    {
        // Create the PDF converter
        PdfConverter pdfConverter = new PdfConverter();

        // Enable header
        pdfConverter.PdfHeaderOptions.ShowHeader = true;
        pdfConverter.PdfHeaderOptions.HeaderText = "Document Header";
        pdfConverter.PdfHeaderOptions.HeaderTextAlignment = HorizontalTextAlign.Center;

        // Enable footer with page numbers
        pdfConverter.PdfFooterOptions.ShowFooter = true;
        pdfConverter.PdfFooterOptions.FooterText = "Page &p; of &P;";
        pdfConverter.PdfFooterOptions.FooterTextAlignment = HorizontalTextAlign.Right;

        // Convert HTML file to PDF
        byte[] pdfBytes = pdfConverter.GetPdfBytesFromHtmlFile("input.html");

        // Save to file
        System.IO.File.WriteAllBytes("output-with-header-footer.pdf", pdfBytes);

        Console.WriteLine("PDF with headers and footers created successfully!");
    }
}

IronPDF Implementation:

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

class Program
{
    static void Main()
    {
        // Create a PDF renderer
        var renderer = new ChromePdfRenderer();

        // Configure header
        renderer.RenderingOptions.TextHeader = new TextHeaderFooter()
        {
            CenterText = "Document Header",
            DrawDividerLine = true
        };

        // Configure footer with page numbers
        renderer.RenderingOptions.TextFooter = new TextHeaderFooter()
        {
            RightText = "Page {page} of {total-pages}",
            DrawDividerLine = true
        };

        // Convert HTML file to PDF
        var pdf = renderer.RenderHtmlFileAsPdf("input.html");

        // Save to file
        pdf.SaveAs("output-with-header-footer.pdf");

        Console.WriteLine("PDF with headers and footers created successfully!");
    }
}

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

class Program
{
    static void Main()
    {
        // Create a PDF renderer
        var renderer = new ChromePdfRenderer();

        // Configure header
        renderer.RenderingOptions.TextHeader = new TextHeaderFooter()
        {
            CenterText = "Document Header",
            DrawDividerLine = true
        };

        // Configure footer with page numbers
        renderer.RenderingOptions.TextFooter = new TextHeaderFooter()
        {
            RightText = "Page {page} of {total-pages}",
            DrawDividerLine = true
        };

        // Convert HTML file to PDF
        var pdf = renderer.RenderHtmlFileAsPdf("input.html");

        // Save to file
        pdf.SaveAs("output-with-header-footer.pdf");

        Console.WriteLine("PDF with headers and footers created successfully!");
    }
}

IronPDF's TextHeaderFooter provides LeftText, CenterText, and RightText properties with optional divider lines. For HTML-based headers, use HtmlHeaderFooter. For more options, see the headers and footers documentation.

License Key Location

ExpertPdf uses per-converter licensing. IronPDF uses a single global license set once at startup:

// ExpertPdf - per converter
pdfConverter.LicenseKey = "EXPERTPDF-LICENSE";

// IronPDF - global, set once
IronPdf.License.LicenseKey = "IRONPDF-LICENSE";

// ExpertPdf - per converter
pdfConverter.LicenseKey = "EXPERTPDF-LICENSE";

// IronPDF - global, set once
IronPdf.License.LicenseKey = "IRONPDF-LICENSE";

Page Numbering Token Conversion

Replace ExpertPdf tokens with IronPDF placeholders:

// ExpertPdf
"Page &p; of &P;"

// IronPDF
"Page {page} of {total-pages}"

// ExpertPdf
"Page &p; of &P;"

// IronPDF
"Page {page} of {total-pages}"

Fragmented Packages Consolidated

ExpertPdf's separate packages (PDFMerge, PDFSecurity, PDFSplit, PdfToImage) are all included in IronPDF's single package:

// ExpertPdf - requires separate PDFMerge package
var merger = new PdfMerge();
merger.AppendPDFFile("file1.pdf");
merger.AppendPDFFile("file2.pdf");
merger.SaveMergedPDFToFile("merged.pdf");

// IronPDF - included in main package
var pdf1 = PdfDocument.FromFile("file1.pdf");
var pdf2 = PdfDocument.FromFile("file2.pdf");
var merged = PdfDocument.Merge(pdf1, pdf2);
merged.SaveAs("merged.pdf");

// ExpertPdf - requires separate PDFMerge package
var merger = new PdfMerge();
merger.AppendPDFFile("file1.pdf");
merger.AppendPDFFile("file2.pdf");
merger.SaveMergedPDFToFile("merged.pdf");

// IronPDF - included in main package
var pdf1 = PdfDocument.FromFile("file1.pdf");
var pdf2 = PdfDocument.FromFile("file2.pdf");
var merged = PdfDocument.Merge(pdf1, pdf2);
merged.SaveAs("merged.pdf");

For more merging options, see the PDF merging documentation.

Custom Page Sizes

ExpertPdf uses points. IronPDF uses millimeters. Convert: points / 72 * 25.4 = mm