How to Migrate from Syncfusion PDF to IronPDF in C#

Understanding Syncfusion PDF Framework

The Syncfusion PDF Framework is a comprehensive library that provides a wide range of functionalities for creating, editing, and securing PDF documents using C#. It comes as a part of Syncfusion's Essential Studio, which includes over a thousand components across multiple platforms.

However, one of its most significant drawbacks is that it cannot be purchased as a standalone product; developers must buy the entire suite of Syncfusion components. This requirement can be cumbersome for teams interested solely in PDF functionalities, especially since this bundle might include tools unnecessary for their projects.

The Bundle Licensing Problem

Syncfusion's licensing model creates significant challenges for teams that only need PDF functionality:

1. Suite-Only Purchase: Cannot buy PDF library standalone—must purchase entire Essential Studio
2. Community License Restrictions: Free tier requires BOTH <$1M revenue AND <5 developers
3. Complex Deployment Licensing: Different licenses for web, desktop, server deployments
4. Annual Renewal Required: Subscription model with yearly costs
5. Per-Developer Pricing: Costs scale linearly with team size
6. Suite Bloat: Includes 1000+ components you may not need

Syncfusion PDF vs IronPDF Comparison

IronPDF provides a more focused approach by offering its PDF capabilities as a standalone product. This difference significantly impacts both cost considerations and ease of integration.

For teams planning .NET 10 and C# 14 adoption through 2025 and 2026, IronPDF's standalone licensing and HTML/CSS-first approach provides flexibility without suite dependencies.

Prerequisites

1. .NET Environment: .NET Framework 4.6.2+ or .NET Core 3.1+ / .NET 5/6/7/8/9+
2. NuGet Access: Ability to install NuGet packages
3. IronPDF License: Obtain your license key from ironpdf.com

NuGet Package Changes

# Remove Syncfusion packages
dotnet remove package Syncfusion.Pdf.Net.Core
dotnet remove package Syncfusion.HtmlToPdfConverter.Net.Windows
dotnet remove package Syncfusion.Licensing

# Install IronPDF
dotnet add package IronPdf

# Remove Syncfusion packages
dotnet remove package Syncfusion.Pdf.Net.Core
dotnet remove package Syncfusion.HtmlToPdfConverter.Net.Windows
dotnet remove package Syncfusion.Licensing

# Install IronPDF
dotnet add package IronPdf

License Configuration

Syncfusion:

// Must register before any Syncfusion calls
Syncfusion.Licensing.SyncfusionLicenseProvider.RegisterLicense("YOUR-SYNCFUSION-KEY");

// Must register before any Syncfusion calls
Syncfusion.Licensing.SyncfusionLicenseProvider.RegisterLicense("YOUR-SYNCFUSION-KEY");

IronPDF:

// One-time at startup
IronPdf.License.LicenseKey = "YOUR-IRONPDF-KEY";

// One-time at startup
IronPdf.License.LicenseKey = "YOUR-IRONPDF-KEY";

Namespace Changes

// Before: Syncfusion PDF
using Syncfusion.Pdf;
using Syncfusion.Pdf.Graphics;
using Syncfusion.Pdf.Parsing;
using Syncfusion.HtmlConverter;
using Syncfusion.Drawing;

// After: IronPDF
using IronPdf;
using IronPdf.Rendering;

// Before: Syncfusion PDF
using Syncfusion.Pdf;
using Syncfusion.Pdf.Graphics;
using Syncfusion.Pdf.Parsing;
using Syncfusion.HtmlConverter;
using Syncfusion.Drawing;

// After: IronPDF
using IronPdf;
using IronPdf.Rendering;

Core API Mappings

Example 1: HTML/URL to PDF Conversion

Before (Syncfusion PDF):

// NuGet: Install-Package Syncfusion.Pdf.Net.Core
using Syncfusion.HtmlConverter;
using Syncfusion.Pdf;
using System.IO;

class Program
{
    static void Main()
    {
        // Initialize HTML to PDF converter
        HtmlToPdfConverter htmlConverter = new HtmlToPdfConverter();

        // Convert URL to PDF
        PdfDocument document = htmlConverter.Convert("https://www.example.com");

        // Save the document
        FileStream fileStream = new FileStream("Output.pdf", FileMode.Create);
        document.Save(fileStream);
        document.Close(true);
        fileStream.Close();
    }
}

// NuGet: Install-Package Syncfusion.Pdf.Net.Core
using Syncfusion.HtmlConverter;
using Syncfusion.Pdf;
using System.IO;

class Program
{
    static void Main()
    {
        // Initialize HTML to PDF converter
        HtmlToPdfConverter htmlConverter = new HtmlToPdfConverter();

        // Convert URL to PDF
        PdfDocument document = htmlConverter.Convert("https://www.example.com");

        // Save the document
        FileStream fileStream = new FileStream("Output.pdf", FileMode.Create);
        document.Save(fileStream);
        document.Close(true);
        fileStream.Close();
    }
}

After (IronPDF):

// NuGet: Install-Package IronPdf
using IronPdf;

class Program
{
    static void Main()
    {
        // Create a PDF from a URL
        var renderer = new ChromePdfRenderer();
        var pdf = renderer.RenderUrlAsPdf("https://www.example.com");

        // Save the PDF
        pdf.SaveAs("Output.pdf");
    }
}

// NuGet: Install-Package IronPdf
using IronPdf;

class Program
{
    static void Main()
    {
        // Create a PDF from a URL
        var renderer = new ChromePdfRenderer();
        var pdf = renderer.RenderUrlAsPdf("https://www.example.com");

        // Save the PDF
        pdf.SaveAs("Output.pdf");
    }
}

This example demonstrates the fundamental API differences. Syncfusion PDF requires an HtmlToPdfConverter instance, calling Convert() which returns a PdfDocument, then manually creating a FileStream, saving, and closing both the document and stream.

IronPDF uses a ChromePdfRenderer with RenderUrlAsPdf() in just three lines of code. No FileStream management, no Close() calls—IronPDF handles cleanup automatically. See the HTML to PDF documentation for comprehensive examples.

Example 2: Creating PDF from Text

Before (Syncfusion PDF):

// NuGet: Install-Package Syncfusion.Pdf.Net.Core
using Syncfusion.Pdf;
using Syncfusion.Pdf.Graphics;
using Syncfusion.Drawing;
using System.IO;

class Program
{
    static void Main()
    {
        // Create a new PDF document
        PdfDocument document = new PdfDocument();

        // Add a page
        PdfPage page = document.Pages.Add();

        // Create a font
        PdfFont font = new PdfStandardFont(PdfFontFamily.Helvetica, 12);

        // Draw text
        page.Graphics.DrawString("Hello, World!", font, PdfBrushes.Black, new PointF(10, 10));

        // Save the document
        FileStream fileStream = new FileStream("Output.pdf", FileMode.Create);
        document.Save(fileStream);
        document.Close(true);
        fileStream.Close();
    }
}

// NuGet: Install-Package Syncfusion.Pdf.Net.Core
using Syncfusion.Pdf;
using Syncfusion.Pdf.Graphics;
using Syncfusion.Drawing;
using System.IO;

class Program
{
    static void Main()
    {
        // Create a new PDF document
        PdfDocument document = new PdfDocument();

        // Add a page
        PdfPage page = document.Pages.Add();

        // Create a font
        PdfFont font = new PdfStandardFont(PdfFontFamily.Helvetica, 12);

        // Draw text
        page.Graphics.DrawString("Hello, World!", font, PdfBrushes.Black, new PointF(10, 10));

        // Save the document
        FileStream fileStream = new FileStream("Output.pdf", FileMode.Create);
        document.Save(fileStream);
        document.Close(true);
        fileStream.Close();
    }
}

After (IronPDF):

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

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

        // Save the document
        pdf.SaveAs("Output.pdf");
    }
}

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

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

        // Save the document
        pdf.SaveAs("Output.pdf");
    }
}

Syncfusion PDF uses a coordinate-based graphics model. You create a PdfDocument, add a PdfPage, create a PdfFont with PdfFontFamily.Helvetica, then call page.Graphics.DrawString() with explicit coordinates (new PointF(10, 10)), font, and brush (PdfBrushes.Black). Finally, you manage FileStream creation and disposal.

IronPDF uses an HTML/CSS-first approach. Instead of coordinates, you write <h1>Hello, World!</h1> and let CSS handle positioning, fonts, and colors. This approach is simpler, more maintainable, and leverages skills developers already have. Learn more in our tutorials.

Example 3: Merging PDF Documents

Before (Syncfusion PDF):

// NuGet: Install-Package Syncfusion.Pdf.Net.Core
using Syncfusion.Pdf;
using Syncfusion.Pdf.Parsing;
using System.IO;

class Program
{
    static void Main()
    {
        // Load the first PDF document
        FileStream stream1 = new FileStream("Document1.pdf", FileMode.Open, FileAccess.Read);
        PdfLoadedDocument loadedDocument1 = new PdfLoadedDocument(stream1);

        // Load the second PDF document
        FileStream stream2 = new FileStream("Document2.pdf", FileMode.Open, FileAccess.Read);
        PdfLoadedDocument loadedDocument2 = new PdfLoadedDocument(stream2);

        // Merge the documents
        PdfDocument finalDocument = new PdfDocument();
        finalDocument.ImportPageRange(loadedDocument1, 0, loadedDocument1.Pages.Count - 1);
        finalDocument.ImportPageRange(loadedDocument2, 0, loadedDocument2.Pages.Count - 1);

        // Save the merged document
        FileStream outputStream = new FileStream("Merged.pdf", FileMode.Create);
        finalDocument.Save(outputStream);

        // Close all documents
        finalDocument.Close(true);
        loadedDocument1.Close(true);
        loadedDocument2.Close(true);
        stream1.Close();
        stream2.Close();
        outputStream.Close();
    }
}

// NuGet: Install-Package Syncfusion.Pdf.Net.Core
using Syncfusion.Pdf;
using Syncfusion.Pdf.Parsing;
using System.IO;

class Program
{
    static void Main()
    {
        // Load the first PDF document
        FileStream stream1 = new FileStream("Document1.pdf", FileMode.Open, FileAccess.Read);
        PdfLoadedDocument loadedDocument1 = new PdfLoadedDocument(stream1);

        // Load the second PDF document
        FileStream stream2 = new FileStream("Document2.pdf", FileMode.Open, FileAccess.Read);
        PdfLoadedDocument loadedDocument2 = new PdfLoadedDocument(stream2);

        // Merge the documents
        PdfDocument finalDocument = new PdfDocument();
        finalDocument.ImportPageRange(loadedDocument1, 0, loadedDocument1.Pages.Count - 1);
        finalDocument.ImportPageRange(loadedDocument2, 0, loadedDocument2.Pages.Count - 1);

        // Save the merged document
        FileStream outputStream = new FileStream("Merged.pdf", FileMode.Create);
        finalDocument.Save(outputStream);

        // Close all documents
        finalDocument.Close(true);
        loadedDocument1.Close(true);
        loadedDocument2.Close(true);
        stream1.Close();
        stream2.Close();
        outputStream.Close();
    }
}

After (IronPDF):

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

class Program
{
    static void Main()
    {
        // Load PDF documents
        var pdf1 = PdfDocument.FromFile("Document1.pdf");
        var pdf2 = PdfDocument.FromFile("Document2.pdf");

        // Merge PDFs
        var merged = PdfDocument.Merge(new List<PdfDocument> { pdf1, pdf2 });

        // Save the merged document
        merged.SaveAs("Merged.pdf");
    }
}

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

class Program
{
    static void Main()
    {
        // Load PDF documents
        var pdf1 = PdfDocument.FromFile("Document1.pdf");
        var pdf2 = PdfDocument.FromFile("Document2.pdf");

        // Merge PDFs
        var merged = PdfDocument.Merge(new List<PdfDocument> { pdf1, pdf2 });

        // Save the merged document
        merged.SaveAs("Merged.pdf");
    }
}

The contrast in merging PDFs is dramatic. Syncfusion PDF requires creating FileStream objects for each input document, loading them as PdfLoadedDocument, creating a new PdfDocument, calling ImportPageRange() with start and end indices for each source, creating an output FileStream, and then closing six separate objects (finalDocument, loadedDocument1, loadedDocument2, stream1, stream2, outputStream).

IronPDF uses PdfDocument.FromFile() to load each PDF and a static PdfDocument.Merge() method that accepts a list of documents. No stream management, no manual page range calculations, no close calls.

Coordinate-Based vs HTML/CSS-First

Syncfusion PDF uses a coordinate-based graphics model inherited from traditional PDF libraries:

// Syncfusion: Manual positioning
page.Graphics.DrawString("Text", font, PdfBrushes.Black, new PointF(100, 200));
page.Graphics.DrawRectangle(brush, new RectangleF(50, 50, 200, 100));

// Syncfusion: Manual positioning
page.Graphics.DrawString("Text", font, PdfBrushes.Black, new PointF(100, 200));
page.Graphics.DrawRectangle(brush, new RectangleF(50, 50, 200, 100));

IronPDF uses HTML/CSS for layout:

// IronPDF: CSS-based positioning
var html = @"
<div style='margin: 50px; padding: 20px; border: 1px solid black;'>
    <p style='color: black;'>Text</p>
</div>";
var pdf = renderer.RenderHtmlAsPdf(html);

// IronPDF: CSS-based positioning
var html = @"
<div style='margin: 50px; padding: 20px; border: 1px solid black;'>
    <p style='color: black;'>Text</p>
</div>";
var pdf = renderer.RenderHtmlAsPdf(html);

The HTML/CSS approach is more intuitive for web developers, easier to maintain, and produces consistent results across different page sizes.

Stream Management vs Automatic Cleanup

Syncfusion PDF requires explicit stream and document disposal:

// Syncfusion: Manual cleanup
FileStream fileStream = new FileStream("Output.pdf", FileMode.Create);
document.Save(fileStream);
document.Close(true);
fileStream.Close();

// Syncfusion: Manual cleanup
FileStream fileStream = new FileStream("Output.pdf", FileMode.Create);
document.Save(fileStream);
document.Close(true);
fileStream.Close();

IronPDF handles cleanup automatically:

// IronPDF: Automatic cleanup
pdf.SaveAs("Output.pdf");

// IronPDF: Automatic cleanup
pdf.SaveAs("Output.pdf");

Pre-Migration

• Inventory all Syncfusion PDF usages in codebase
• Document licensing costs and deployment requirements
• Identify PdfGrid, PdfGraphics, and HtmlToPdfConverter usages
• Obtain IronPDF license key from ironpdf.com

Code Updates

• Remove Syncfusion packages (Syncfusion.Pdf.Net.Core, Syncfusion.HtmlToPdfConverter.Net.Windows, Syncfusion.Licensing)
• Install IronPdf NuGet package
• Update namespace imports (using Syncfusion.Pdf; → using IronPdf;)
• Replace Syncfusion.Licensing.SyncfusionLicenseProvider.RegisterLicense() with IronPdf.License.LicenseKey = "..."
• Replace HtmlToPdfConverter.Convert() with ChromePdfRenderer.RenderUrlAsPdf() or RenderHtmlAsPdf()
• Replace PdfDocument + Pages.Add() + Graphics.DrawString() with ChromePdfRenderer.RenderHtmlAsPdf()
• Replace PdfLoadedDocument with PdfDocument.FromFile()
• Replace ImportPageRange() with PdfDocument.Merge()
• Replace document.Save(stream) with pdf.SaveAs(path)
• Remove all document.Close(true) and stream.Close() calls
• Replace PdfGrid with HTML <table> elements
• Replace PdfStandardFont with CSS font-family
• Replace PdfBrushes with CSS color properties

Testing

• Visual comparison of PDF output
• Verify CSS rendering improvements (flexbox, grid now work)
• Test text extraction
• Test merging and splitting
• Performance comparison