HiQPdf vs IronPDF: Technical Comparison Guide

HTML and URL to PDF Conversion

The most fundamental operations demonstrate the API design differences.

HiQPdf:

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

class Program
{
    static void Main()
    {
        HtmlToPdf htmlToPdfConverter = new HtmlToPdf();
        byte[] pdfBuffer = htmlToPdfConverter.ConvertUrlToMemory("https://example.com");
        System.IO.File.WriteAllBytes("output.pdf", pdfBuffer);

        // Convert HTML string
        string html = "<h1>Hello World</h1><p>This is a PDF document.</p>";
        byte[] pdfFromHtml = htmlToPdfConverter.ConvertHtmlToMemory(html, "");
        System.IO.File.WriteAllBytes("fromhtml.pdf", pdfFromHtml);
    }
}

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

class Program
{
    static void Main()
    {
        HtmlToPdf htmlToPdfConverter = new HtmlToPdf();
        byte[] pdfBuffer = htmlToPdfConverter.ConvertUrlToMemory("https://example.com");
        System.IO.File.WriteAllBytes("output.pdf", pdfBuffer);

        // Convert HTML string
        string html = "<h1>Hello World</h1><p>This is a PDF document.</p>";
        byte[] pdfFromHtml = htmlToPdfConverter.ConvertHtmlToMemory(html, "");
        System.IO.File.WriteAllBytes("fromhtml.pdf", pdfFromHtml);
    }
}

IronPDF:

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

class Program
{
    static void Main()
    {
        var renderer = new ChromePdfRenderer();
        var pdf = renderer.RenderUrlAsPdf("https://example.com");
        pdf.SaveAs("output.pdf");

        // Convert HTML string
        string html = "<h1>Hello World</h1><p>This is a PDF document.</p>";
        var pdfFromHtml = renderer.RenderHtmlAsPdf(html);
        pdfFromHtml.SaveAs("fromhtml.pdf");
    }
}

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

class Program
{
    static void Main()
    {
        var renderer = new ChromePdfRenderer();
        var pdf = renderer.RenderUrlAsPdf("https://example.com");
        pdf.SaveAs("output.pdf");

        // Convert HTML string
        string html = "<h1>Hello World</h1><p>This is a PDF document.</p>";
        var pdfFromHtml = renderer.RenderHtmlAsPdf(html);
        pdfFromHtml.SaveAs("fromhtml.pdf");
    }
}

HiQPdf creates an HtmlToPdf converter, calls ConvertUrlToMemory() or ConvertHtmlToMemory() to get raw byte[] data, then manually writes to disk using File.WriteAllBytes(). The ConvertHtmlToMemory() method requires a second parameter for the base URL (empty string if not needed).

IronPDF creates a ChromePdfRenderer, calls RenderUrlAsPdf() or RenderHtmlAsPdf() to get a PdfDocument object, then saves directly with SaveAs(). The API is more concise with object-oriented document handling.

For advanced HTML rendering options, explore the HTML to PDF conversion guide.

Merging Multiple PDFs

PDF merging demonstrates the different approaches to document manipulation.

HiQPdf:

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

class Program
{
    static void Main()
    {
        // Create first PDF
        HtmlToPdf converter1 = new HtmlToPdf();
        byte[] pdf1 = converter1.ConvertHtmlToMemory("<h1>First Document</h1>", "");
        System.IO.File.WriteAllBytes("doc1.pdf", pdf1);

        // Create second PDF
        HtmlToPdf converter2 = new HtmlToPdf();
        byte[] pdf2 = converter2.ConvertHtmlToMemory("<h1>Second Document</h1>", "");
        System.IO.File.WriteAllBytes("doc2.pdf", pdf2);

        // Merge PDFs
        PdfDocument document1 = PdfDocument.FromFile("doc1.pdf");
        PdfDocument document2 = PdfDocument.FromFile("doc2.pdf");
        document1.AddDocument(document2);
        document1.WriteToFile("merged.pdf");
    }
}

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

class Program
{
    static void Main()
    {
        // Create first PDF
        HtmlToPdf converter1 = new HtmlToPdf();
        byte[] pdf1 = converter1.ConvertHtmlToMemory("<h1>First Document</h1>", "");
        System.IO.File.WriteAllBytes("doc1.pdf", pdf1);

        // Create second PDF
        HtmlToPdf converter2 = new HtmlToPdf();
        byte[] pdf2 = converter2.ConvertHtmlToMemory("<h1>Second Document</h1>", "");
        System.IO.File.WriteAllBytes("doc2.pdf", pdf2);

        // Merge PDFs
        PdfDocument document1 = PdfDocument.FromFile("doc1.pdf");
        PdfDocument document2 = PdfDocument.FromFile("doc2.pdf");
        document1.AddDocument(document2);
        document1.WriteToFile("merged.pdf");
    }
}

IronPDF:

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

class Program
{
    static void Main()
    {
        var renderer = new ChromePdfRenderer();

        // Create first PDF
        var pdf1 = renderer.RenderHtmlAsPdf("<h1>First Document</h1>");
        pdf1.SaveAs("doc1.pdf");

        // Create second PDF
        var pdf2 = renderer.RenderHtmlAsPdf("<h1>Second Document</h1>");
        pdf2.SaveAs("doc2.pdf");

        // Merge PDFs
        var merged = PdfDocument.Merge(pdf1, pdf2);
        merged.SaveAs("merged.pdf");
    }
}

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

class Program
{
    static void Main()
    {
        var renderer = new ChromePdfRenderer();

        // Create first PDF
        var pdf1 = renderer.RenderHtmlAsPdf("<h1>First Document</h1>");
        pdf1.SaveAs("doc1.pdf");

        // Create second PDF
        var pdf2 = renderer.RenderHtmlAsPdf("<h1>Second Document</h1>");
        pdf2.SaveAs("doc2.pdf");

        // Merge PDFs
        var merged = PdfDocument.Merge(pdf1, pdf2);
        merged.SaveAs("merged.pdf");
    }
}

HiQPdf requires saving PDFs to disk first, loading them with PdfDocument.FromFile(), then using AddDocument() to append one to another, and finally WriteToFile() to save the result. This modifies the first document in place.

IronPDF can merge documents directly in memory using the static PdfDocument.Merge() method, which returns a new merged document. This approach is cleaner and doesn't require intermediate file I/O.

Headers and Footers with Page Numbers

Header and footer configuration shows the different approaches to dynamic content.

HiQPdf:

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

class Program
{
    static void Main()
    {
        HtmlToPdf htmlToPdfConverter = new HtmlToPdf();

        // Add header
        htmlToPdfConverter.Document.Header.Height = 50;
        HtmlToPdfVariableElement headerHtml = new HtmlToPdfVariableElement("<div style='text-align:center'>Page Header</div>", "");
        htmlToPdfConverter.Document.Header.Add(headerHtml);

        // Add footer with page number
        htmlToPdfConverter.Document.Footer.Height = 50;
        HtmlToPdfVariableElement footerHtml = new HtmlToPdfVariableElement("<div style='text-align:center'>Page {CrtPage} of {PageCount}</div>", "");
        htmlToPdfConverter.Document.Footer.Add(footerHtml);

        byte[] pdfBuffer = htmlToPdfConverter.ConvertHtmlToMemory("<h1>Document with Headers and Footers</h1>", "");
        System.IO.File.WriteAllBytes("header-footer.pdf", pdfBuffer);
    }
}

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

class Program
{
    static void Main()
    {
        HtmlToPdf htmlToPdfConverter = new HtmlToPdf();

        // Add header
        htmlToPdfConverter.Document.Header.Height = 50;
        HtmlToPdfVariableElement headerHtml = new HtmlToPdfVariableElement("<div style='text-align:center'>Page Header</div>", "");
        htmlToPdfConverter.Document.Header.Add(headerHtml);

        // Add footer with page number
        htmlToPdfConverter.Document.Footer.Height = 50;
        HtmlToPdfVariableElement footerHtml = new HtmlToPdfVariableElement("<div style='text-align:center'>Page {CrtPage} of {PageCount}</div>", "");
        htmlToPdfConverter.Document.Footer.Add(footerHtml);

        byte[] pdfBuffer = htmlToPdfConverter.ConvertHtmlToMemory("<h1>Document with Headers and Footers</h1>", "");
        System.IO.File.WriteAllBytes("header-footer.pdf", pdfBuffer);
    }
}

IronPDF:

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

class Program
{
    static void Main()
    {
        var renderer = new ChromePdfRenderer();

        // Configure header and footer
        renderer.RenderingOptions.TextHeader = new TextHeaderFooter()
        {
            CenterText = "Page Header",
            FontSize = 12
        };

        renderer.RenderingOptions.TextFooter = new TextHeaderFooter()
        {
            CenterText = "Page {page} of {total-pages}",
            FontSize = 10
        };

        var pdf = renderer.RenderHtmlAsPdf("<h1>Document with Headers and Footers</h1>");
        pdf.SaveAs("header-footer.pdf");
    }
}

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

class Program
{
    static void Main()
    {
        var renderer = new ChromePdfRenderer();

        // Configure header and footer
        renderer.RenderingOptions.TextHeader = new TextHeaderFooter()
        {
            CenterText = "Page Header",
            FontSize = 12
        };

        renderer.RenderingOptions.TextFooter = new TextHeaderFooter()
        {
            CenterText = "Page {page} of {total-pages}",
            FontSize = 10
        };

        var pdf = renderer.RenderHtmlAsPdf("<h1>Document with Headers and Footers</h1>");
        pdf.SaveAs("header-footer.pdf");
    }
}

HiQPdf configures headers and footers through Document.Header and Document.Footer properties, setting Height and adding HtmlToPdfVariableElement objects. Page number placeholders use {CrtPage} for current page and {PageCount} for total pages.

IronPDF uses RenderingOptions.TextHeader and RenderingOptions.TextFooter with TextHeaderFooter objects. Properties like CenterText and FontSize provide direct configuration. Page number placeholders use {page} and {total-pages}.

Learn more about header and footer configuration in the IronPDF tutorials.

Main Class Mapping

Conversion Method Mapping

Property Mapping

Placeholder Syntax Mapping

Header and footer placeholders differ between the libraries:

HiQPdf Strengths

• HTML5/CSS3 Support: Provides HTML5 and CSS3 rendering capabilities
• Established Library: Commercial library with existing user base

HiQPdf Considerations

• WebKit Engine: Older rendering technology with limited modern JavaScript support
• 3-Page Limit: Free version significantly restricted
• Fragmented Packages: Multiple NuGet packages for different platforms
• Unclear .NET Support: Documentation doesn't explicitly clarify modern .NET compatibility
• Complex Property Chains: Verbose configuration through nested properties
• Point-Based Units: Uses points (72 per inch) for measurements

IronPDF Strengths

• Chromium Engine: Modern rendering with full JavaScript support
• Unified Package: Single NuGet package for all platforms
• Full Trial: 30-day full-featured trial
• Modern .NET Support: Documented for .NET 6, 7, 8, 9, 10
• Clean API: Fluent RenderingOptions configuration
• Comprehensive Resources: Extensive tutorials and documentation

IronPDF Considerations

• Commercial License: Required for production use
• Millimeter Units: Uses millimeters rather than points for margins