The C# PDF Library

HTML to PDF

using IronPdf;

// Disable local disk access or cross-origin requests
Installation.EnableWebSecurity = true;

// Instantiate Renderer
var renderer = new ChromePdfRenderer();

// Create a PDF from a HTML string using C#
var pdf = renderer.RenderHtmlAsPdf("<h1>Hello World</h1>");

// Export to a file or Stream
pdf.SaveAs("output.pdf");

// Advanced Example with HTML Assets
// Load external html assets: Images, CSS and JavaScript.
// An optional BasePath 'C:\site\assets\' is set as the file location to load assets from
var myAdvancedPdf = renderer.RenderHtmlAsPdf("<img src='icons/iron.png'>", @"C:\site\assets\");
myAdvancedPdf.SaveAs("html-with-assets.pdf");

using IronPdf;

// Disable local disk access or cross-origin requests
Installation.EnableWebSecurity = true;

// Instantiate Renderer
var renderer = new ChromePdfRenderer();

// Create a PDF from a HTML string using C#
var pdf = renderer.RenderHtmlAsPdf("<h1>Hello World</h1>");

// Export to a file or Stream
pdf.SaveAs("output.pdf");

// Advanced Example with HTML Assets
// Load external html assets: Images, CSS and JavaScript.
// An optional BasePath 'C:\site\assets\' is set as the file location to load assets from
var myAdvancedPdf = renderer.RenderHtmlAsPdf("<img src='icons/iron.png'>", @"C:\site\assets\");
myAdvancedPdf.SaveAs("html-with-assets.pdf");

PM >Install-Package IronPdf

Install-Package IronPdf

MIGRATION GUIDES

How to Migrate from HiQPdf to IronPDF in C#

Curtis Chau

Updated: August 1, 2026

HiQPdf is a commercial HTML-to-PDF library published by HiQPdf Software (current HiQPdf 18.0.2 on nuget.org, February 2026). Common reasons developers evaluate alternatives:

Restrictive Free Version: HiQPdf.Free caps output at 3 pages per document - useful for evaluation, not production workloads requiring complete document generation.
WebKit on the Classic Line: The Classic HiQPdf package uses an older WebKit-based engine that can struggle with modern JavaScript frameworks. HiQPdf does ship a Chromium-based variant (HiQPdf.NG / HiQPdf.Chromium.Windows, plus a Linux build), but most existing code targets the Classic engine.
.NET Support Spread Across Packages: .NET Framework, .NET Core, and .NET Standard 2.0 are all supported, but split across separate NuGet IDs (HiQPdf, HiQPdf_NetCore, HiQPdf.NG, HiQPdf.Chromium.Windows, HiQPdf_x64) you have to pick between.
Fragmented Packages: Multiple NuGet IDs for different platforms (HiQPdf, HiQPdf.Free, HiQPdf_NetCore, HiQPdf.NG, HiQPdf.Chromium.Windows) complicate dependency management.
Verbose Configuration: Requires setup through Document, Header, Footer property chains rather than a fluent rendering-options API.
Per-Developer Licensing Adds Up: $245 Startup / $495 Developer / $795 Team / $1,095 Enterprise (perpetual, first year of updates included).

HiQPdf vs IronPDF Comparison

Aspect	HiQPdf	IronPDF
Rendering Engine	WebKit (Classic `HiQPdf`) or Chromium (`HiQPdf.NG` / `HiQPdf.Chromium.Windows`)	Modern Chromium
Free Tier	`HiQPdf.Free` 3-page limit	30-day full trial
Modern JS Support	Limited on Classic; modern on NG/Chromium	Full (React, Angular, Vue)
.NET Core/5+ Support	Supported, but split across multiple NuGet packages	Single unified package
API Design	Property chains	Fluent rendering options
CSS3 Support	Partial on Classic; full on NG	Full support
Documentation	Fragmented across product lines	Comprehensive
NuGet Package	Multiple variants	Single package

IronPDF documents support for current .NET versions (.NET Framework 4.6.2+, .NET 6, 7, 8, 9) on a modern Chromium rendering engine.

Migration Complexity Assessment

Estimated Effort by Feature

Feature	Migration Complexity
HTML to PDF	Very Low
URL to PDF	Very Low
Merge PDFs	Low
Headers/Footers	Medium
Page Size/Margins	Low
TriggerMode/Delays	Low

Paradigm Shift

The fundamental shift in this HiQPdf migration is from property chain configuration to fluent rendering options:

HiQPdf:   converter.Document.Header.Height = 50;
          converter.Document.Header.Add(new HtmlToPdfVariableElement(...));
          
IronPDF:  renderer.RenderingOptions.TextHeader = new TextHeaderFooter() { ... };

HiQPdf:   converter.Document.Header.Height = 50;
          converter.Document.Header.Add(new HtmlToPdfVariableElement(...));
          
IronPDF:  renderer.RenderingOptions.TextHeader = new TextHeaderFooter() { ... };

Text

Before You Start

Prerequisites

.NET Version: IronPDF supports .NET Framework 4.6.2+ and .NET Core 3.1+ / .NET 5+
License Key: Obtain your IronPDF license key from ironpdf.com
Remove HiQPdf: Plan to remove all HiQPdf NuGet package variants

Identify All HiQPdf Usage

# Find HiQPdf namespace usage
grep -r "using HiQPdf\|HtmlToPdf\|PdfDocument" --include="*.cs" .

# Find header/footer usage
grep -r "\.Header\.\|\.Footer\.\|HtmlToPdfVariableElement" --include="*.cs" .

# Find placeholder syntax
grep -r "CrtPage\|PageCount" --include="*.cs" .

# Find NuGet references
grep -r "HiQPdf" --include="*.csproj" .

# Find HiQPdf namespace usage
grep -r "using HiQPdf\|HtmlToPdf\|PdfDocument" --include="*.cs" .

# Find header/footer usage
grep -r "\.Header\.\|\.Footer\.\|HtmlToPdfVariableElement" --include="*.cs" .

# Find placeholder syntax
grep -r "CrtPage\|PageCount" --include="*.cs" .

# Find NuGet references
grep -r "HiQPdf" --include="*.csproj" .

SHELL

NuGet Package Changes

# Remove all HiQPdf variants
dotnet remove package HiQPdf
dotnet remove package HiQPdf.Free
dotnet remove package HiQPdf_NetCore
dotnet remove package HiQPdf_x64
dotnet remove package HiQPdf.NG
dotnet remove package HiQPdf.Chromium.Windows

# Install IronPDF (single package for all platforms)
dotnet add package IronPdf

# Remove all HiQPdf variants
dotnet remove package HiQPdf
dotnet remove package HiQPdf.Free
dotnet remove package HiQPdf_NetCore
dotnet remove package HiQPdf_x64
dotnet remove package HiQPdf.NG
dotnet remove package HiQPdf.Chromium.Windows

# Install IronPDF (single package for all platforms)
dotnet add package IronPdf

SHELL

Quick Start Migration

Step 1: Update License Configuration

Before (HiQPdf):

HtmlToPdf converter = new HtmlToPdf();
converter.SerialNumber = "HIQPDF-SERIAL-NUMBER";

HtmlToPdf converter = new HtmlToPdf();
converter.SerialNumber = "HIQPDF-SERIAL-NUMBER";

Dim converter As New HtmlToPdf()
converter.SerialNumber = "HIQPDF-SERIAL-NUMBER"

Dim converter As New HtmlToPdf()
converter.SerialNumber = "HIQPDF-SERIAL-NUMBER"

After (IronPDF):

// Set globally at application startup
IronPdf.License.LicenseKey = "YOUR-IRONPDF-LICENSE-KEY";

// Set globally at application startup
IronPdf.License.LicenseKey = "YOUR-IRONPDF-LICENSE-KEY";

net

net

Step 2: Update Namespace Imports

// Before (HiQPdf)
using HiQPdf;

// After (IronPDF)
using IronPdf;
using IronPdf.Rendering;

// Before (HiQPdf)
using HiQPdf;

// After (IronPDF)
using IronPdf;
using IronPdf.Rendering;

Imports IronPdf
Imports IronPdf.Rendering

Imports IronPdf
Imports IronPdf.Rendering

Complete API Reference

Main Class Mapping

HiQPdf Class	IronPDF Class
`HtmlToPdf`	`ChromePdfRenderer`
`PdfDocument`	`PdfDocument`
`HtmlToPdfVariableElement`	`TextHeaderFooter` or `HtmlHeaderFooter`

Conversion Method Mapping

HiQPdf Method	IronPDF Method
`ConvertHtmlToMemory(html, baseUrl)`	`RenderHtmlAsPdf(html)`
`ConvertUrlToMemory(url)`	`RenderUrlAsPdf(url)`
`File.WriteAllBytes(path, bytes)`	`pdf.SaveAs(path)`

PDF Document Method Mapping

HiQPdf Method	IronPDF Method
`PdfDocument.FromFile(path)`	`PdfDocument.FromFile(path)`
`document1.AddDocument(document2)`	`PdfDocument.Merge(pdf1, pdf2)`
`document.WriteToFile(path)`	`pdf.SaveAs(path)`

Header/Footer Placeholder Mapping

HiQPdf Placeholder	IronPDF Placeholder	Description
`{CrtPage}`	`{page}`	Current page number
`{PageCount}`	`{total-pages}`	Total page count

Code Migration Examples

Example 1: HTML to PDF Conversion

Before (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);
    }
}

' NuGet: Install-Package HiQPdf
Imports HiQPdf
Imports System

Module Program
    Sub Main()
        Dim htmlToPdfConverter As New HtmlToPdf()
        Dim pdfBuffer As Byte() = htmlToPdfConverter.ConvertUrlToMemory("https://example.com")
        System.IO.File.WriteAllBytes("output.pdf", pdfBuffer)
        
        ' Convert HTML string
        Dim html As String = "<h1>Hello World</h1><p>This is a PDF document.</p>"
        Dim pdfFromHtml As Byte() = htmlToPdfConverter.ConvertHtmlToMemory(html, "")
        System.IO.File.WriteAllBytes("fromhtml.pdf", pdfFromHtml)
    End Sub
End Module

' NuGet: Install-Package HiQPdf
Imports HiQPdf
Imports System

Module Program
    Sub Main()
        Dim htmlToPdfConverter As New HtmlToPdf()
        Dim pdfBuffer As Byte() = htmlToPdfConverter.ConvertUrlToMemory("https://example.com")
        System.IO.File.WriteAllBytes("output.pdf", pdfBuffer)
        
        ' Convert HTML string
        Dim html As String = "<h1>Hello World</h1><p>This is a PDF document.</p>"
        Dim pdfFromHtml As Byte() = htmlToPdfConverter.ConvertHtmlToMemory(html, "")
        System.IO.File.WriteAllBytes("fromhtml.pdf", pdfFromHtml)
    End Sub
End Module

After (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");
    }
}

' NuGet: Install-Package IronPdf
Imports IronPdf
Imports System

Module Program
    Sub Main()
        Dim renderer = New ChromePdfRenderer()
        Dim pdf = renderer.RenderUrlAsPdf("https://example.com")
        pdf.SaveAs("output.pdf")
        
        ' Convert HTML string
        Dim html As String = "<h1>Hello World</h1><p>This is a PDF document.</p>"
        Dim pdfFromHtml = renderer.RenderHtmlAsPdf(html)
        pdfFromHtml.SaveAs("fromhtml.pdf")
    End Sub
End Module

' NuGet: Install-Package IronPdf
Imports IronPdf
Imports System

Module Program
    Sub Main()
        Dim renderer = New ChromePdfRenderer()
        Dim pdf = renderer.RenderUrlAsPdf("https://example.com")
        pdf.SaveAs("output.pdf")
        
        ' Convert HTML string
        Dim html As String = "<h1>Hello World</h1><p>This is a PDF document.</p>"
        Dim pdfFromHtml = renderer.RenderHtmlAsPdf(html)
        pdfFromHtml.SaveAs("fromhtml.pdf")
    End Sub
End Module

The HiQPdf approach requires creating an HtmlToPdf instance, calling ConvertUrlToMemory() or ConvertHtmlToMemory() to get a byte array, then manually writing bytes to a file. IronPDF's ChromePdfRenderer returns a PdfDocument object with a direct SaveAs() method, eliminating the manual file writing step. The modern Chromium engine also provides better rendering for complex HTML/CSS/JavaScript content. See the HTML to PDF documentation for additional rendering options.

Example 2: Merge Multiple PDFs

Before (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");
    }
}

' NuGet: Install-Package HiQPdf
Imports HiQPdf
Imports System

Module Program
    Sub Main()
        ' Create first PDF
        Dim converter1 As New HtmlToPdf()
        Dim pdf1 As Byte() = converter1.ConvertHtmlToMemory("<h1>First Document</h1>", "")
        System.IO.File.WriteAllBytes("doc1.pdf", pdf1)

        ' Create second PDF
        Dim converter2 As New HtmlToPdf()
        Dim pdf2 As Byte() = converter2.ConvertHtmlToMemory("<h1>Second Document</h1>", "")
        System.IO.File.WriteAllBytes("doc2.pdf", pdf2)

        ' Merge PDFs
        Dim document1 As PdfDocument = PdfDocument.FromFile("doc1.pdf")
        Dim document2 As PdfDocument = PdfDocument.FromFile("doc2.pdf")
        document1.AddDocument(document2)
        document1.WriteToFile("merged.pdf")
    End Sub
End Module

' NuGet: Install-Package HiQPdf
Imports HiQPdf
Imports System

Module Program
    Sub Main()
        ' Create first PDF
        Dim converter1 As New HtmlToPdf()
        Dim pdf1 As Byte() = converter1.ConvertHtmlToMemory("<h1>First Document</h1>", "")
        System.IO.File.WriteAllBytes("doc1.pdf", pdf1)

        ' Create second PDF
        Dim converter2 As New HtmlToPdf()
        Dim pdf2 As Byte() = converter2.ConvertHtmlToMemory("<h1>Second Document</h1>", "")
        System.IO.File.WriteAllBytes("doc2.pdf", pdf2)

        ' Merge PDFs
        Dim document1 As PdfDocument = PdfDocument.FromFile("doc1.pdf")
        Dim document2 As PdfDocument = PdfDocument.FromFile("doc2.pdf")
        document1.AddDocument(document2)
        document1.WriteToFile("merged.pdf")
    End Sub
End Module

After (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");
    }
}

' NuGet: Install-Package IronPdf
Imports IronPdf
Imports System

Module Program
    Sub Main()
        Dim renderer = New ChromePdfRenderer()

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

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

        ' Merge PDFs
        Dim merged = PdfDocument.Merge(pdf1, pdf2)
        merged.SaveAs("merged.pdf")
    End Sub
End Module

' NuGet: Install-Package IronPdf
Imports IronPdf
Imports System

Module Program
    Sub Main()
        Dim renderer = New ChromePdfRenderer()

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

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

        ' Merge PDFs
        Dim merged = PdfDocument.Merge(pdf1, pdf2)
        merged.SaveAs("merged.pdf")
    End Sub
End Module

The HiQPdf approach requires loading documents from files using PdfDocument.FromFile(), calling AddDocument() on the first document to append the second, then using WriteToFile() to save. IronPDF provides a cleaner static PdfDocument.Merge() method that accepts multiple PdfDocument objects directly - no intermediate file operations required. Learn more about merging and splitting PDFs.

Example 3: PDF Headers and Footers with Page Numbers

Before (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);
    }
}

' NuGet: Install-Package HiQPdf
Imports HiQPdf
Imports System

Class Program
    Shared Sub Main()
        Dim htmlToPdfConverter As New HtmlToPdf()

        ' Add header
        htmlToPdfConverter.Document.Header.Height = 50
        Dim headerHtml As 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
        Dim footerHtml As New HtmlToPdfVariableElement("<div style='text-align:center'>Page {CrtPage} of {PageCount}</div>", "")
        htmlToPdfConverter.Document.Footer.Add(footerHtml)

        Dim pdfBuffer As Byte() = htmlToPdfConverter.ConvertHtmlToMemory("<h1>Document with Headers and Footers</h1>", "")
        System.IO.File.WriteAllBytes("header-footer.pdf", pdfBuffer)
    End Sub
End Class

' NuGet: Install-Package HiQPdf
Imports HiQPdf
Imports System

Class Program
    Shared Sub Main()
        Dim htmlToPdfConverter As New HtmlToPdf()

        ' Add header
        htmlToPdfConverter.Document.Header.Height = 50
        Dim headerHtml As 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
        Dim footerHtml As New HtmlToPdfVariableElement("<div style='text-align:center'>Page {CrtPage} of {PageCount}</div>", "")
        htmlToPdfConverter.Document.Footer.Add(footerHtml)

        Dim pdfBuffer As Byte() = htmlToPdfConverter.ConvertHtmlToMemory("<h1>Document with Headers and Footers</h1>", "")
        System.IO.File.WriteAllBytes("header-footer.pdf", pdfBuffer)
    End Sub
End Class

After (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");
    }
}

' NuGet: Install-Package IronPdf
Imports IronPdf
Imports IronPdf.Rendering
Imports System

Module Program
    Sub Main()
        Dim renderer = New ChromePdfRenderer()

        ' Configure header and footer
        renderer.RenderingOptions.TextHeader = New TextHeaderFooter() With {
            .CenterText = "Page Header",
            .FontSize = 12
        }

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

        Dim pdf = renderer.RenderHtmlAsPdf("<h1>Document with Headers and Footers</h1>")
        pdf.SaveAs("header-footer.pdf")
    End Sub
End Module

' NuGet: Install-Package IronPdf
Imports IronPdf
Imports IronPdf.Rendering
Imports System

Module Program
    Sub Main()
        Dim renderer = New ChromePdfRenderer()

        ' Configure header and footer
        renderer.RenderingOptions.TextHeader = New TextHeaderFooter() With {
            .CenterText = "Page Header",
            .FontSize = 12
        }

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

        Dim pdf = renderer.RenderHtmlAsPdf("<h1>Document with Headers and Footers</h1>")
        pdf.SaveAs("header-footer.pdf")
    End Sub
End Module

The HiQPdf approach requires setting Document.Header.Height, creating HtmlToPdfVariableElement objects, and calling Add() on the header/footer sections. Page number placeholders use {CrtPage} and {PageCount} syntax. IronPDF provides a cleaner TextHeaderFooter configuration with CenterText properties and different placeholder syntax: {page} and {total-pages}. See the headers and footers documentation for additional options including HTML-based headers.

Critical Migration Notes

Placeholder Syntax Change

The most important change for documents with page numbers is the placeholder syntax:

// HiQPdf placeholders
"Page {CrtPage} of {PageCount}"

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

// HiQPdf placeholders
"Page {CrtPage} of {PageCount}"

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

' HiQPdf placeholders
"Page {CrtPage} of {PageCount}"

' IronPDF placeholders
"Page {page} of {total-pages}"

' HiQPdf placeholders
"Page {CrtPage} of {PageCount}"

' IronPDF placeholders
"Page {page} of {total-pages}"

Complete placeholder mapping:

{CrtPage} → {page}
{PageCount} → {total-pages}

Merge Method Difference

HiQPdf modifies the first document in place:

// HiQPdf: Modifies document1
document1.AddDocument(document2);
document1.WriteToFile("merged.pdf");

// HiQPdf: Modifies document1
document1.AddDocument(document2);
document1.WriteToFile("merged.pdf");

' HiQPdf: Modifies document1
document1.AddDocument(document2)
document1.WriteToFile("merged.pdf")

' HiQPdf: Modifies document1
document1.AddDocument(document2)
document1.WriteToFile("merged.pdf")

IronPDF returns a new merged document:

// IronPDF: Returns new document
var merged = PdfDocument.Merge(pdf1, pdf2);
merged.SaveAs("merged.pdf");

// IronPDF: Returns new document
var merged = PdfDocument.Merge(pdf1, pdf2);
merged.SaveAs("merged.pdf");

' IronPDF: Returns new document
Dim merged = PdfDocument.Merge(pdf1, pdf2)
merged.SaveAs("merged.pdf")

' IronPDF: Returns new document
Dim merged = PdfDocument.Merge(pdf1, pdf2)
merged.SaveAs("merged.pdf")

No 3-Page Limit

HiQPdf's free version caps output at 3 pages with watermarks. IronPDF generates complete documents without artificial limitations during the trial period.

Reuse ChromePdfRenderer

Unlike HiQPdf where you might create new HtmlToPdf instances for each conversion, IronPDF's ChromePdfRenderer should be reused:

// IronPDF: Create once, reuse
var renderer = new ChromePdfRenderer();
var pdf1 = renderer.RenderHtmlAsPdf(html1);
var pdf2 = renderer.RenderHtmlAsPdf(html2);

// IronPDF: Create once, reuse
var renderer = new ChromePdfRenderer();
var pdf1 = renderer.RenderHtmlAsPdf(html1);
var pdf2 = renderer.RenderHtmlAsPdf(html2);

' IronPDF: Create once, reuse
Dim renderer As New ChromePdfRenderer()
Dim pdf1 = renderer.RenderHtmlAsPdf(html1)
Dim pdf2 = renderer.RenderHtmlAsPdf(html2)

' IronPDF: Create once, reuse
Dim renderer As New ChromePdfRenderer()
Dim pdf1 = renderer.RenderHtmlAsPdf(html1)
Dim pdf2 = renderer.RenderHtmlAsPdf(html2)

Troubleshooting

Issue 1: HtmlToPdf Not Found

Problem: HtmlToPdf class doesn't exist in IronPDF.

Solution: Replace with ChromePdfRenderer:

// HiQPdf
HtmlToPdf htmlToPdfConverter = new HtmlToPdf();

// IronPDF
var renderer = new ChromePdfRenderer();

// HiQPdf
HtmlToPdf htmlToPdfConverter = new HtmlToPdf();

// IronPDF
var renderer = new ChromePdfRenderer();

' HiQPdf
Dim htmlToPdfConverter As New HtmlToPdf()

' IronPDF
Dim renderer As New ChromePdfRenderer()

' HiQPdf
Dim htmlToPdfConverter As New HtmlToPdf()

' IronPDF
Dim renderer As New ChromePdfRenderer()

Issue 2: ConvertHtmlToMemory Not Found

Problem: ConvertHtmlToMemory() method doesn't exist.

Solution: Use RenderHtmlAsPdf():

// HiQPdf
byte[] pdfBytes = converter.ConvertHtmlToMemory(html, "");

// IronPDF
var pdf = renderer.RenderHtmlAsPdf(html);
byte[] pdfBytes = pdf.BinaryData;

// HiQPdf
byte[] pdfBytes = converter.ConvertHtmlToMemory(html, "");

// IronPDF
var pdf = renderer.RenderHtmlAsPdf(html);
byte[] pdfBytes = pdf.BinaryData;

' HiQPdf
Dim pdfBytes As Byte() = converter.ConvertHtmlToMemory(html, "")

' IronPDF
Dim pdf = renderer.RenderHtmlAsPdf(html)
Dim pdfBytes As Byte() = pdf.BinaryData

' HiQPdf
Dim pdfBytes As Byte() = converter.ConvertHtmlToMemory(html, "")

' IronPDF
Dim pdf = renderer.RenderHtmlAsPdf(html)
Dim pdfBytes As Byte() = pdf.BinaryData

Issue 3: Page Number Placeholders Not Working

Problem: {CrtPage} and {PageCount} appear literally in output.

Solution: Update to IronPDF placeholder syntax:

// HiQPdf syntax (won't work)
"Page {CrtPage} of {PageCount}"

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

// HiQPdf syntax (won't work)
"Page {CrtPage} of {PageCount}"

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

' HiQPdf syntax (won't work)
"Page {CrtPage} of {PageCount}"

' IronPDF syntax
"Page {page} of {total-pages}"

' HiQPdf syntax (won't work)
"Page {CrtPage} of {PageCount}"

' IronPDF syntax
"Page {page} of {total-pages}"

Issue 4: HtmlToPdfVariableElement Not Found

Problem: HtmlToPdfVariableElement class doesn't exist.

Solution: Use TextHeaderFooter or HtmlHeaderFooter:

// HiQPdf
HtmlToPdfVariableElement headerHtml = new HtmlToPdfVariableElement("<div>Header</div>", "");
converter.Document.Header.Add(headerHtml);

// IronPDF
renderer.RenderingOptions.TextHeader = new TextHeaderFooter()
{
    CenterText = "Header",
    FontSize = 12
};

// HiQPdf
HtmlToPdfVariableElement headerHtml = new HtmlToPdfVariableElement("<div>Header</div>", "");
converter.Document.Header.Add(headerHtml);

// IronPDF
renderer.RenderingOptions.TextHeader = new TextHeaderFooter()
{
    CenterText = "Header",
    FontSize = 12
};

' HiQPdf
Dim headerHtml As New HtmlToPdfVariableElement("<div>Header</div>", "")
converter.Document.Header.Add(headerHtml)

' IronPDF
renderer.RenderingOptions.TextHeader = New TextHeaderFooter() With {
    .CenterText = "Header",
    .FontSize = 12
}

' HiQPdf
Dim headerHtml As New HtmlToPdfVariableElement("<div>Header</div>", "")
converter.Document.Header.Add(headerHtml)

' IronPDF
renderer.RenderingOptions.TextHeader = New TextHeaderFooter() With {
    .CenterText = "Header",
    .FontSize = 12
}

Migration Checklist

Pre-Migration

Inventory all HiQPdf API calls in codebase
Document current page sizes, margins, and settings
Identify header/footer configurations and placeholders
Obtain IronPDF license key
Test IronPDF in development environment

Code Migration

Remove all HiQPdf NuGet packages (all variants)
Install IronPDF NuGet package: dotnet add package IronPdf
Update namespace imports
Replace HtmlToPdf with ChromePdfRenderer
Convert ConvertHtmlToMemory() to RenderHtmlAsPdf()
Convert ConvertUrlToMemory() to RenderUrlAsPdf()
Update header/footer placeholders ({CrtPage} → {page}, {PageCount} → {total-pages})
Replace HtmlToPdfVariableElement with TextHeaderFooter
Update merge operations (AddDocument → PdfDocument.Merge)
Add license key initialization at startup

Testing

Test HTML to PDF conversion
Test URL to PDF conversion
Verify header/footer rendering
Verify page number placeholders
Test PDF merging
Test JavaScript-heavy pages (now supported with Chromium)

Post-Migration

Remove HiQPdf serial number from configuration
Update documentation
Monitor for any rendering differences

Please note: HiQPdf is a registered trademark of its respective owner. This site is not affiliated with, endorsed by, or sponsored by HiQPdf Software. All product names, logos, and brands are property of their respective owners. Comparisons are for informational purposes only and reflect publicly available information at the time of writing.

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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