Syncfusion PDF vs IronPDF: Technical Comparison Guide

Syncfusion PDF: Coordinate-Based Graphics

Syncfusion PDF uses a traditional coordinate-based graphics model where developers specify exact positions for text, shapes, and images:

// 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();
    }
}

This approach requires:

• Manual page management with document.Pages.Add()
• Creating font objects with PdfStandardFont
• Explicit coordinate positioning with PointF(10, 10)
• Manual stream management and explicit Close() calls
• Multiple using statements for different namespaces

IronPDF: HTML/CSS-First Approach

IronPDF uses HTML and CSS for content creation, leveraging web technologies developers already know:

// 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");
    }
}

The RenderHtmlAsPdf method converts HTML content directly to PDF. No coordinate calculations, no manual font objects, no stream management—the Chromium engine handles layout automatically.

Syncfusion PDF HTML Conversion

Syncfusion PDF uses a separate HTML converter that requires explicit document and stream management:

// 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();
    }
}

This approach requires:

• Separate HtmlToPdfConverter class
• BlinkBinaries for HTML rendering
• Manual FileStream creation and management
• Explicit document.Close(true) calls
• Multiple cleanup operations

IronPDF HTML Conversion

IronPDF provides streamlined URL-to-PDF conversion:

// 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");
    }
}

The RenderUrlAsPdf method navigates to the URL, renders the page with JavaScript execution using the native Chromium engine, and captures the result. No separate converter class, no stream management, no explicit cleanup.

Syncfusion PDF Merge

Syncfusion PDF requires manual stream management and page-by-page importing:

// 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();
    }
}

This approach requires:

• Separate FileStream objects for each document
• PdfLoadedDocument for reading existing PDFs
• Manual ImportPageRange() calls with page indices
• Creating a new PdfDocument for the result
• Six separate Close() calls for cleanup
• Significant boilerplate code

IronPDF Merge

IronPDF provides a declarative merge operation:

// 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 PdfDocument.Merge() method accepts a list of documents and returns a combined result. No stream management, no page index calculations, no manual cleanup—automatic resource management handles everything.

Core Document Classes

Graphics and Drawing

Fonts and Text

Colors and Brushes

Tables

Security

HTML Conversion

Syncfusion PDF Installation

# Multiple packages may be needed
dotnet add package Syncfusion.Pdf.Net.Core
dotnet add package Syncfusion.HtmlToPdfConverter.Net.Windows
dotnet add package Syncfusion.Pdf.Imaging.Net.Core
dotnet add package Syncfusion.Licensing

# Multiple packages may be needed
dotnet add package Syncfusion.Pdf.Net.Core
dotnet add package Syncfusion.HtmlToPdfConverter.Net.Windows
dotnet add package Syncfusion.Pdf.Imaging.Net.Core
dotnet add package Syncfusion.Licensing

License registration:

// 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 Installation

# Single package
dotnet add package IronPdf

# Single package
dotnet add package IronPdf

License configuration:

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

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