How to Migrate from Rotativa to IronPDF in C#

Understanding Rotativa

Rotativa has long been a popular choice among developers for generating PDFs in C#. It leverages the wkhtmltopdf tool to convert HTML content into PDF format. Rotativa is an open-source library specifically designed for ASP.NET MVC applications. However, while it has attracted a significant audience, Rotativa's reliance on an outdated technology stack presents challenges that might not be immediately evident to every developer.

At its core, Rotativa provides a simple way to integrate PDF generation into ASP.NET MVC projects, taking advantage of wkhtmltopdf for its backend functionalities.

Critical Security Advisory

Rotativa wraps wkhtmltopdf, which has CRITICAL UNPATCHED SECURITY VULNERABILITIES.

wkhtmltopdf was officially abandoned in December 2022. The maintainers explicitly stated they will NOT fix security vulnerabilities. Every application using Rotativa is permanently exposed.

How the Attack Works

<iframe src="http://169.254.169.254/latest/meta-data/iam/security-credentials/"></iframe>
<img src="http://internal-database:5432/admin" />

<iframe src="http://169.254.169.254/latest/meta-data/iam/security-credentials/"></iframe>
<img src="http://internal-database:5432/admin" />

Impact:

• Access AWS/Azure/GCP cloud metadata endpoints
• Steal internal API data and credentials
• Port scan internal networks
• Exfiltrate sensitive configuration

The Technology Crisis

Rotativa wraps wkhtmltopdf, which uses:

• Qt WebKit 4.8 (from 2012)
• No Flexbox support
• No CSS Grid support
• Broken JavaScript execution
• No ES6+ support

Rotativa vs IronPDF Comparison

For teams planning .NET 10 and C# 14 adoption through 2025 and 2026, IronPDF provides modern Chromium rendering and cross-platform support that Rotativa cannot offer.

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 Rotativa
dotnet remove package Rotativa
dotnet remove package Rotativa.AspNetCore

# Install IronPDF
dotnet add package IronPdf

# Remove Rotativa
dotnet remove package Rotativa
dotnet remove package Rotativa.AspNetCore

# Install IronPDF
dotnet add package IronPdf

Remove wkhtmltopdf Binaries

Delete these files from your project:

• wkhtmltopdf.exe
• wkhtmltox.dll
• Any Rotativa/ folders

These are the source of CVE-2022-35583. IronPDF needs no native binaries.

License Configuration

// Add in Program.cs or Startup.cs
IronPdf.License.LicenseKey = "YOUR-LICENSE-KEY";

// Add in Program.cs or Startup.cs
IronPdf.License.LicenseKey = "YOUR-LICENSE-KEY";

' Add in Program.vb or Startup.vb
IronPdf.License.LicenseKey = "YOUR-LICENSE-KEY"

Namespace Changes

// Before: Rotativa
using Rotativa;
using Rotativa.Options;
using Rotativa.AspNetCore;

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

// Before: Rotativa
using Rotativa;
using Rotativa.Options;
using Rotativa.AspNetCore;

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

' Before: Rotativa
Imports Rotativa
Imports Rotativa.Options
Imports Rotativa.AspNetCore

' After: IronPDF
Imports IronPdf
Imports IronPdf.Rendering

Core Class Mappings

Page Placeholder Conversion

Example 1: HTML to PDF Conversion

Before (Rotativa):

// NuGet: Install-Package Rotativa.Core
using Microsoft.AspNetCore.Mvc;
using Rotativa.AspNetCore;
using System.Threading.Tasks;

namespace RotativaExample
{
    public class PdfController : Controller
    {
        public async Task<IActionResult> GeneratePdf()
        {
            var htmlContent = "<h1>Hello World</h1><p>This is a PDF document.</p>";

            // Rotativa requires returning a ViewAsPdf result from MVC controller
            return new ViewAsPdf()
            {
                ViewName = "PdfView",
                PageSize = Rotativa.AspNetCore.Options.Size.A4
            };
        }
    }
}

// NuGet: Install-Package Rotativa.Core
using Microsoft.AspNetCore.Mvc;
using Rotativa.AspNetCore;
using System.Threading.Tasks;

namespace RotativaExample
{
    public class PdfController : Controller
    {
        public async Task<IActionResult> GeneratePdf()
        {
            var htmlContent = "<h1>Hello World</h1><p>This is a PDF document.</p>";

            // Rotativa requires returning a ViewAsPdf result from MVC controller
            return new ViewAsPdf()
            {
                ViewName = "PdfView",
                PageSize = Rotativa.AspNetCore.Options.Size.A4
            };
        }
    }
}

Imports Microsoft.AspNetCore.Mvc
Imports Rotativa.AspNetCore
Imports System.Threading.Tasks

Namespace RotativaExample
    Public Class PdfController
        Inherits Controller

        Public Async Function GeneratePdf() As Task(Of IActionResult)
            Dim htmlContent As String = "<h1>Hello World</h1><p>This is a PDF document.</p>"

            ' Rotativa requires returning a ViewAsPdf result from MVC controller
            Return New ViewAsPdf() With {
                .ViewName = "PdfView",
                .PageSize = Rotativa.AspNetCore.Options.Size.A4
            }
        End Function
    End Class
End Namespace

After (IronPDF):

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

namespace IronPdfExample
{
    class Program
    {
        static void Main(string[] args)
        {
            var renderer = new ChromePdfRenderer();
            var htmlContent = "<h1>Hello World</h1><p>This is a PDF document.</p>";

            var pdf = renderer.RenderHtmlAsPdf(htmlContent);
            pdf.SaveAs("output.pdf");

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

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

namespace IronPdfExample
{
    class Program
    {
        static void Main(string[] args)
        {
            var renderer = new ChromePdfRenderer();
            var htmlContent = "<h1>Hello World</h1><p>This is a PDF document.</p>";

            var pdf = renderer.RenderHtmlAsPdf(htmlContent);
            pdf.SaveAs("output.pdf");

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

Imports IronPdf
Imports System

Namespace IronPdfExample
    Class Program
        Shared Sub Main(ByVal args As String())
            Dim renderer = New ChromePdfRenderer()
            Dim htmlContent = "<h1>Hello World</h1><p>This is a PDF document.</p>"

            Dim pdf = renderer.RenderHtmlAsPdf(htmlContent)
            pdf.SaveAs("output.pdf")

            Console.WriteLine("PDF generated successfully!")
        End Sub
    End Class
End Namespace

This example demonstrates the fundamental architectural difference. Rotativa requires returning a ViewAsPdf result from an MVC controller action, tying you to the ASP.NET MVC framework. The pattern only works within the MVC request pipeline and requires a Razor view to render.

IronPDF works anywhere: console applications, web APIs, Blazor, Razor Pages, or any .NET project type. You call RenderHtmlAsPdf() with an HTML string and save the result. No MVC controller required, no view dependency. See the HTML to PDF documentation for comprehensive examples.

Example 2: URL to PDF Conversion

Before (Rotativa):

// NuGet: Install-Package Rotativa.Core
using Microsoft.AspNetCore.Mvc;
using Rotativa.AspNetCore;
using System.Threading.Tasks;

namespace RotativaExample
{
    public class UrlPdfController : Controller
    {
        public async Task<IActionResult> ConvertUrlToPdf()
        {
            // Rotativa works within MVC framework and returns ActionResult
            return new UrlAsPdf("https://www.example.com")
            {
                FileName = "webpage.pdf",
                PageSize = Rotativa.AspNetCore.Options.Size.A4,
                PageOrientation = Rotativa.AspNetCore.Options.Orientation.Portrait
            };
        }
    }
}

// NuGet: Install-Package Rotativa.Core
using Microsoft.AspNetCore.Mvc;
using Rotativa.AspNetCore;
using System.Threading.Tasks;

namespace RotativaExample
{
    public class UrlPdfController : Controller
    {
        public async Task<IActionResult> ConvertUrlToPdf()
        {
            // Rotativa works within MVC framework and returns ActionResult
            return new UrlAsPdf("https://www.example.com")
            {
                FileName = "webpage.pdf",
                PageSize = Rotativa.AspNetCore.Options.Size.A4,
                PageOrientation = Rotativa.AspNetCore.Options.Orientation.Portrait
            };
        }
    }
}

' NuGet: Install-Package Rotativa.Core
Imports Microsoft.AspNetCore.Mvc
Imports Rotativa.AspNetCore
Imports System.Threading.Tasks

Namespace RotativaExample
    Public Class UrlPdfController
        Inherits Controller

        Public Async Function ConvertUrlToPdf() As Task(Of IActionResult)
            ' Rotativa works within MVC framework and returns ActionResult
            Return New UrlAsPdf("https://www.example.com") With {
                .FileName = "webpage.pdf",
                .PageSize = Rotativa.AspNetCore.Options.Size.A4,
                .PageOrientation = Rotativa.AspNetCore.Options.Orientation.Portrait
            }
        End Function
    End Class
End Namespace

After (IronPDF):

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

namespace IronPdfExample
{
    class Program
    {
        static void Main(string[] args)
        {
            var renderer = new ChromePdfRenderer();

            var pdf = renderer.RenderUrlAsPdf("https://www.example.com");
            pdf.SaveAs("webpage.pdf");

            Console.WriteLine("URL converted to PDF successfully!");
        }
    }
}

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

namespace IronPdfExample
{
    class Program
    {
        static void Main(string[] args)
        {
            var renderer = new ChromePdfRenderer();

            var pdf = renderer.RenderUrlAsPdf("https://www.example.com");
            pdf.SaveAs("webpage.pdf");

            Console.WriteLine("URL converted to PDF successfully!");
        }
    }
}

Imports IronPdf
Imports System

Namespace IronPdfExample
    Class Program
        Shared Sub Main(ByVal args As String())
            Dim renderer = New ChromePdfRenderer()

            Dim pdf = renderer.RenderUrlAsPdf("https://www.example.com")
            pdf.SaveAs("webpage.pdf")

            Console.WriteLine("URL converted to PDF successfully!")
        End Sub
    End Class
End Namespace

Rotativa's UrlAsPdf class requires returning an ActionResult from an MVC controller. IronPDF's RenderUrlAsPdf() method can be called from any context and returns a PdfDocument object directly. The URL rendering uses modern Chromium instead of wkhtmltopdf's vulnerable and outdated WebKit engine. Learn more in our tutorials.

Example 3: Headers and Footers with Page Numbers

Before (Rotativa):

// NuGet: Install-Package Rotativa.Core
using Microsoft.AspNetCore.Mvc;
using Rotativa.AspNetCore;
using Rotativa.AspNetCore.Options;
using System.Threading.Tasks;

namespace RotativaExample
{
    public class HeaderFooterController : Controller
    {
        public async Task<IActionResult> GeneratePdfWithHeaderFooter()
        {
            return new ViewAsPdf("Report")
            {
                PageSize = Size.A4,
                PageMargins = new Margins(20, 10, 20, 10),
                CustomSwitches = "--header-center \"Page Header\" --footer-center \"Page [page] of [toPage]\""
            };
        }
    }
}

// NuGet: Install-Package Rotativa.Core
using Microsoft.AspNetCore.Mvc;
using Rotativa.AspNetCore;
using Rotativa.AspNetCore.Options;
using System.Threading.Tasks;

namespace RotativaExample
{
    public class HeaderFooterController : Controller
    {
        public async Task<IActionResult> GeneratePdfWithHeaderFooter()
        {
            return new ViewAsPdf("Report")
            {
                PageSize = Size.A4,
                PageMargins = new Margins(20, 10, 20, 10),
                CustomSwitches = "--header-center \"Page Header\" --footer-center \"Page [page] of [toPage]\""
            };
        }
    }
}

Imports Microsoft.AspNetCore.Mvc
Imports Rotativa.AspNetCore
Imports Rotativa.AspNetCore.Options
Imports System.Threading.Tasks

Namespace RotativaExample
    Public Class HeaderFooterController
        Inherits Controller

        Public Async Function GeneratePdfWithHeaderFooter() As Task(Of IActionResult)
            Return New ViewAsPdf("Report") With {
                .PageSize = Size.A4,
                .PageMargins = New Margins(20, 10, 20, 10),
                .CustomSwitches = "--header-center ""Page Header"" --footer-center ""Page [page] of [toPage]"""
            }
        End Function
    End Class
End Namespace

After (IronPDF):

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

namespace IronPdfExample
{
    class Program
    {
        static void Main(string[] args)
        {
            var renderer = new ChromePdfRenderer();

            renderer.RenderingOptions.TextHeader = new TextHeaderFooter()
            {
                CenterText = "Page Header",
                DrawDividerLine = true
            };

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

            var htmlContent = "<h1>Report Title</h1><p>Report content goes here.</p>";
            var pdf = renderer.RenderHtmlAsPdf(htmlContent);
            pdf.SaveAs("report.pdf");

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

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

namespace IronPdfExample
{
    class Program
    {
        static void Main(string[] args)
        {
            var renderer = new ChromePdfRenderer();

            renderer.RenderingOptions.TextHeader = new TextHeaderFooter()
            {
                CenterText = "Page Header",
                DrawDividerLine = true
            };

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

            var htmlContent = "<h1>Report Title</h1><p>Report content goes here.</p>";
            var pdf = renderer.RenderHtmlAsPdf(htmlContent);
            pdf.SaveAs("report.pdf");

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

Imports IronPdf
Imports IronPdf.Rendering
Imports System

Namespace IronPdfExample
    Class Program
        Shared Sub Main(ByVal args As String())
            Dim renderer = New ChromePdfRenderer()

            renderer.RenderingOptions.TextHeader = New TextHeaderFooter() With {
                .CenterText = "Page Header",
                .DrawDividerLine = True
            }

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

            Dim htmlContent = "<h1>Report Title</h1><p>Report content goes here.</p>"
            Dim pdf = renderer.RenderHtmlAsPdf(htmlContent)
            pdf.SaveAs("report.pdf")

            Console.WriteLine("PDF with headers and footers created successfully!")
        End Sub
    End Class
End Namespace

Rotativa uses CustomSwitches to pass command-line arguments to wkhtmltopdf, including header and footer configuration with placeholders like [page] and [toPage]. This string-based approach is error-prone and hard to validate at compile time.

IronPDF uses strongly-typed TextHeaderFooter objects with properties like CenterText and DrawDividerLine. The placeholder syntax changes from [page] to {page} and from [toPage] to {total-pages}. Typed properties provide IntelliSense, compile-time checking, and no risk of typos.

PDF Merging

var merged = PdfDocument.Merge(pdf1, pdf2, pdf3);
merged.SaveAs("complete.pdf");

var merged = PdfDocument.Merge(pdf1, pdf2, pdf3);
merged.SaveAs("complete.pdf");

Dim merged = PdfDocument.Merge(pdf1, pdf2, pdf3)
merged.SaveAs("complete.pdf")

Digital Signatures

var signature = new PdfSignature("certificate.pfx", "password");
pdf.Sign(signature);

var signature = new PdfSignature("certificate.pfx", "password");
pdf.Sign(signature);

Dim signature = New PdfSignature("certificate.pfx", "password")
pdf.Sign(signature)

Password Protection

pdf.SecuritySettings.UserPassword = "secret";

pdf.SecuritySettings.UserPassword = "secret";

pdf.SecuritySettings.UserPassword = "secret"

Watermarks

pdf.ApplyWatermark("<h1 style='color:red; opacity:0.3;'>DRAFT</h1>");

pdf.ApplyWatermark("<h1 style='color:red; opacity:0.3;'>DRAFT</h1>");

IRON VB CONVERTER ERROR developers@ironsoftware.com

PDF/A Archival Compliance

pdf.SaveAsPdfA("archive.pdf", PdfAVersions.PdfA3b);

pdf.SaveAsPdfA("archive.pdf", PdfAVersions.PdfA3b);

pdf.SaveAsPdfA("archive.pdf", PdfAVersions.PdfA3b)

Modern CSS Support

// This now works (broke in Rotativa)
var html = @"
    <div style='display: flex; justify-content: space-between;'>
        <div>Left</div>
        <div>Right</div>
    </div>
    <div style='display: grid; grid-template-columns: 1fr 1fr 1fr;'>
        <div>Col 1</div><div>Col 2</div><div>Col 3</div>
    </div>";
var pdf = renderer.RenderHtmlAsPdf(html);  // Works!

// This now works (broke in Rotativa)
var html = @"
    <div style='display: flex; justify-content: space-between;'>
        <div>Left</div>
        <div>Right</div>
    </div>
    <div style='display: grid; grid-template-columns: 1fr 1fr 1fr;'>
        <div>Col 1</div><div>Col 2</div><div>Col 3</div>
    </div>";
var pdf = renderer.RenderHtmlAsPdf(html);  // Works!

' This now works (broke in Rotativa)
Dim html As String = "
    <div style='display: flex; justify-content: space-between;'>
        <div>Left</div>
        <div>Right</div>
    </div>
    <div style='display: grid; grid-template-columns: 1fr 1fr 1fr;'>
        <div>Col 1</div><div>Col 2</div><div>Col 3</div>
    </div>"
Dim pdf = renderer.RenderHtmlAsPdf(html)  ' Works!

Pre-Migration

• Identify all Rotativa usage in codebase
• Document CustomSwitches used for conversion to RenderingOptions
• Note header/footer placeholder syntax for conversion ([page] → {page})
• Obtain IronPDF license key from ironpdf.com

Package Changes

• Remove Rotativa and Rotativa.AspNetCore NuGet packages
• Delete wkhtmltopdf binaries (wkhtmltopdf.exe, wkhtmltox.dll)
• Install IronPdf NuGet package

Code Changes

• Update namespace imports (using Rotativa; → using IronPdf;)
• Replace ViewAsPdf with ChromePdfRenderer + RenderHtmlAsPdf()
• Replace UrlAsPdf with RenderUrlAsPdf()
• Convert CustomSwitches to RenderingOptions properties
• Update placeholder syntax ([page] → {page}, [topage] → {total-pages})
• Replace PageMargins with individual MarginTop/MarginBottom/MarginLeft/MarginRight
• Change to async pattern where appropriate
• Add license initialization at application startup

Post-Migration

• Verify all PDF generation works correctly
• Compare PDF output quality (Chromium renders more accurately)
• Verify CSS rendering improvements (Flexbox/Grid now work)
• Test JavaScript execution (now reliable with Chromium)
• Verify security scan passes (no more CVE-2022-35583 flags)
• Update Docker configurations to remove wkhtmltopdf installation