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MIGRATION GUIDES

How to Migrate from Api2pdf to IronPDF in C#

Curtis Chau
Curtis Chau
Published:

Api2pdf offers a cloud-based service for generating PDFs, but sending sensitive documents to external servers can lead to security risks, compliance issues, and ongoing costs that can add up over time. This guide provides a detailed migration path from Api2pdf to IronPDF—a native .NET PDF library that processes documents entirely on your own infrastructure, removing data transmission concerns and converting per-conversion costs into a one-time investment.

Why Consider Moving from Api2pdf?

While Api2pdf provides convenient cloud-based PDF generation, several factors lead development teams to look for on-premises alternatives for their PDF generation needs.

Security and Compliance Concerns

Api2pdf operates as a cloud-based service where your sensitive HTML and documents are sent to third-party servers for processing. This creates significant concerns for organizations handling regulated data.

RiskApi2pdfIronPDF
Data TransmissionAll content sent to external serversProcesses locally on your infrastructure
GDPR ComplianceData crosses jurisdictionsData never leaves your environment
HIPAA CompliancePHI transmitted externallyPHI stays within your systems
SOC 2Third-party dependencyFull control over data handling
PCI DSSCard data potentially exposedNo external transmission

Cost Accumulation Over Time

Api2pdf charges approximately $0.005 per conversion indefinitely, while IronPDF offers a one-time perpetual license. For applications generating significant PDF volumes, the cost difference becomes substantial:

VolumeApi2pdf (Annual)IronPDF (One-Time)
10,000 PDFs/month~$600/year$749 (Lite)
50,000 PDFs/month~$3,000/year$749 (Lite)
100,000 PDFs/month~$6,000/year$1,499 (Plus)

IronPDF pays for itself within months for most production applications.

Performance and Availability

Api2pdf requires network round-trips that add 2-5 seconds of latency to every PDF generation request. IronPDF processes locally in 100-500 milliseconds. Additionally, IronPDF works fully offline and in air-gapped environments—critical for applications that can't depend on external service availability.

Api2pdf vs. IronPDF: Key Differences

AspectApi2pdfIronPDF
Data HandlingSent to third-party cloud serversProcessed locally on your infrastructure
PricingPay-per-conversion (~$0.005/PDF)One-time perpetual license
Latency2-5 seconds (network round-trip)100-500ms (local processing)
OfflineNot availableWorks fully offline
InstallationAPI key + HTTP clientSimple NuGet package
ComplianceGDPR/HIPAA concerns (data leaves network)Full compliance control

Step-by-Step Migration Process

Step 1: Update NuGet Packages

Remove the Api2pdf package and install IronPDF:

# Remove Api2pdf
dotnet remove package Api2Pdf

# Install IronPDF
dotnet add package IronPdf
# Remove Api2pdf
dotnet remove package Api2Pdf

# Install IronPDF
dotnet add package IronPdf
SHELL

Or via Package Manager Console:

Uninstall-Package Api2Pdf
Install-Package IronPdf

Step 2: Update Namespace References

Replace Api2pdf namespaces with IronPDF:

// Remove these
using Api2Pdf;
using Api2Pdf.DotNet;

// Add these
using IronPdf;
using IronPdf.Rendering;
// Remove these
using Api2Pdf;
using Api2Pdf.DotNet;

// Add these
using IronPdf;
using IronPdf.Rendering;
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Step 3: Configure the License Key

Set the IronPDF license key at application startup:

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

// Or configure via appsettings.json:
// { "IronPdf.LicenseKey": "YOUR-IRONPDF-LICENSE-KEY" }
// Set once at application startup
IronPdf.License.LicenseKey = "YOUR-IRONPDF-LICENSE-KEY";

// Or configure via appsettings.json:
// { "IronPdf.LicenseKey": "YOUR-IRONPDF-LICENSE-KEY" }
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Step 4: Remove API Key Configuration

IronPDF runs locally and doesn't require API keys:

// Remove this Api2pdf pattern
var client = new Api2PdfClient("API_KEY");

// Just create the renderer directly
var renderer = new ChromePdfRenderer();
// Remove this Api2pdf pattern
var client = new Api2PdfClient("API_KEY");

// Just create the renderer directly
var renderer = new ChromePdfRenderer();
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Complete API Migration Reference

Core Class Mapping

Api2pdf ClassIronPDF EquivalentNotes
Api2PdfClientChromePdfRendererMain rendering class
Api2PdfResultPdfDocumentRepresents the PDF
HeadlessChromeOptionsChromePdfRenderOptionsRendering configuration

Method Mapping

Api2pdf MethodIronPDF MethodNotes
client.HeadlessChrome.FromHtmlAsync(html)renderer.RenderHtmlAsPdf(html)HTML to PDF
client.HeadlessChrome.FromUrlAsync(url)renderer.RenderUrlAsPdf(url)URL to PDF
response.Pdf (URL)pdf.SaveAs(path)Save to file
response.Pdf (download)pdf.BinaryDataGet as byte array
client.PdfSharp.MergePdfsAsync(urls)PdfDocument.Merge(pdfs)Merge PDFs
client.PdfSharp.SetPasswordAsync(url, pwd)pdf.SecuritySettings.OwnerPasswordPassword protection

Rendering Options Mapping

Api2pdf OptionIronPDF OptionNotes
Landscape = trueRenderingOptions.PaperOrientation = LandscapePage orientation
PageSize = "A4"RenderingOptions.PaperSize = PdfPaperSize.A4Paper size
PrintBackground = trueRenderingOptions.PrintHtmlBackgrounds = trueBackground colors
MarginTop, etc.RenderingOptions.MarginTop, etc.Margins in mm
Delay = 5000RenderingOptions.WaitFor.RenderDelay(5000)Wait before render

Code Migration Examples

HTML to PDF Conversion

The most common Api2pdf operation demonstrates the fundamental shift—from cloud API calls to local processing.

Api2pdf Implementation:

// NuGet: Install-Package Api2Pdf.DotNet
using System;
using System.Threading.Tasks;
using Api2Pdf.DotNet;

class Program
{
    static async Task Main(string[] args)
    {
        var a2pClient = new Api2PdfClient("your-api-key");
        var apiResponse = await a2pClient.HeadlessChrome.FromHtmlAsync("<h1>Hello World</h1>");
        Console.WriteLine(apiResponse.Pdf);
    }
}
// NuGet: Install-Package Api2Pdf.DotNet
using System;
using System.Threading.Tasks;
using Api2Pdf.DotNet;

class Program
{
    static async Task Main(string[] args)
    {
        var a2pClient = new Api2PdfClient("your-api-key");
        var apiResponse = await a2pClient.HeadlessChrome.FromHtmlAsync("<h1>Hello World</h1>");
        Console.WriteLine(apiResponse.Pdf);
    }
}
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IronPDF Implementation:

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

class Program
{
    static void Main(string[] args)
    {
        var renderer = new ChromePdfRenderer();
        var pdf = renderer.RenderHtmlAsPdf("<h1>Hello World</h1>");
        pdf.SaveAs("output.pdf");
        Console.WriteLine("PDF created successfully");
    }
}
// NuGet: Install-Package IronPdf
using System;
using IronPdf;

class Program
{
    static void Main(string[] args)
    {
        var renderer = new ChromePdfRenderer();
        var pdf = renderer.RenderHtmlAsPdf("<h1>Hello World</h1>");
        pdf.SaveAs("output.pdf");
        Console.WriteLine("PDF created successfully");
    }
}
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IronPDF eliminates the network round-trip, API key management, and the separate download step required by Api2pdf's URL-based response pattern.

URL to PDF Conversion

Api2pdf Implementation:

// NuGet: Install-Package Api2Pdf.DotNet
using System;
using System.Threading.Tasks;
using Api2Pdf.DotNet;

class Program
{
    static async Task Main(string[] args)
    {
        var a2pClient = new Api2PdfClient("your-api-key");
        var apiResponse = await a2pClient.HeadlessChrome.FromUrlAsync("https://www.example.com");
        Console.WriteLine(apiResponse.Pdf);
    }
}
// NuGet: Install-Package Api2Pdf.DotNet
using System;
using System.Threading.Tasks;
using Api2Pdf.DotNet;

class Program
{
    static async Task Main(string[] args)
    {
        var a2pClient = new Api2PdfClient("your-api-key");
        var apiResponse = await a2pClient.HeadlessChrome.FromUrlAsync("https://www.example.com");
        Console.WriteLine(apiResponse.Pdf);
    }
}
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IronPDF Implementation:

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

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("PDF created from URL successfully");
    }
}
// NuGet: Install-Package IronPdf
using System;
using IronPdf;

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("PDF created from URL successfully");
    }
}
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HTML File to PDF with Options

Api2pdf Implementation:

// NuGet: Install-Package Api2Pdf.DotNet
using System;
using System.IO;
using System.Threading.Tasks;
using Api2Pdf.DotNet;

class Program
{
    static async Task Main(string[] args)
    {
        var a2pClient = new Api2PdfClient("your-api-key");
        string html = File.ReadAllText("input.html");
        var options = new HeadlessChromeOptions
        {
            Landscape = true,
            PrintBackground = true
        };
        var apiResponse = await a2pClient.HeadlessChrome.FromHtmlAsync(html, options);
        Console.WriteLine(apiResponse.Pdf);
    }
}
// NuGet: Install-Package Api2Pdf.DotNet
using System;
using System.IO;
using System.Threading.Tasks;
using Api2Pdf.DotNet;

class Program
{
    static async Task Main(string[] args)
    {
        var a2pClient = new Api2PdfClient("your-api-key");
        string html = File.ReadAllText("input.html");
        var options = new HeadlessChromeOptions
        {
            Landscape = true,
            PrintBackground = true
        };
        var apiResponse = await a2pClient.HeadlessChrome.FromHtmlAsync(html, options);
        Console.WriteLine(apiResponse.Pdf);
    }
}
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IronPDF Implementation:

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

class Program
{
    static void Main(string[] args)
    {
        var renderer = new ChromePdfRenderer();
        renderer.RenderingOptions.PaperOrientation = IronPdf.Rendering.PdfPaperOrientation.Landscape;
        renderer.RenderingOptions.CssMediaType = IronPdf.Rendering.PdfCssMediaType.Print;
        string html = File.ReadAllText("input.html");
        var pdf = renderer.RenderHtmlAsPdf(html);
        pdf.SaveAs("output.pdf");
        Console.WriteLine("PDF created with options successfully");
    }
}
// NuGet: Install-Package IronPdf
using System;
using System.IO;
using IronPdf;

class Program
{
    static void Main(string[] args)
    {
        var renderer = new ChromePdfRenderer();
        renderer.RenderingOptions.PaperOrientation = IronPdf.Rendering.PdfPaperOrientation.Landscape;
        renderer.RenderingOptions.CssMediaType = IronPdf.Rendering.PdfCssMediaType.Print;
        string html = File.ReadAllText("input.html");
        var pdf = renderer.RenderHtmlAsPdf(html);
        pdf.SaveAs("output.pdf");
        Console.WriteLine("PDF created with options successfully");
    }
}
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IronPDF configures rendering options directly on the renderer object rather than passing them as a separate options parameter to each API call.

Merging Multiple PDFs

Api2pdf Implementation:

using Api2Pdf.DotNet;

var a2pClient = new Api2PdfClient("YOUR_API_KEY");

var pdfUrls = new List<string>
{
    "https://example.com/pdf1.pdf",
    "https://example.com/pdf2.pdf",
    "https://example.com/pdf3.pdf"
};

var request = new PdfMergeRequest { Urls = pdfUrls };
var response = await a2pClient.PdfSharp.MergePdfsAsync(request);

if (response.Success)
{
    // Download merged PDF from response.Pdf URL
}
using Api2Pdf.DotNet;

var a2pClient = new Api2PdfClient("YOUR_API_KEY");

var pdfUrls = new List<string>
{
    "https://example.com/pdf1.pdf",
    "https://example.com/pdf2.pdf",
    "https://example.com/pdf3.pdf"
};

var request = new PdfMergeRequest { Urls = pdfUrls };
var response = await a2pClient.PdfSharp.MergePdfsAsync(request);

if (response.Success)
{
    // Download merged PDF from response.Pdf URL
}
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IronPDF Implementation:

using IronPdf;

// Load PDFs from files
var pdf1 = PdfDocument.FromFile("document1.pdf");
var pdf2 = PdfDocument.FromFile("document2.pdf");
var pdf3 = PdfDocument.FromFile("document3.pdf");

// Merge all PDFs
var merged = PdfDocument.Merge(pdf1, pdf2, pdf3);
merged.SaveAs("merged.pdf");
using IronPdf;

// Load PDFs from files
var pdf1 = PdfDocument.FromFile("document1.pdf");
var pdf2 = PdfDocument.FromFile("document2.pdf");
var pdf3 = PdfDocument.FromFile("document3.pdf");

// Merge all PDFs
var merged = PdfDocument.Merge(pdf1, pdf2, pdf3);
merged.SaveAs("merged.pdf");
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IronPDF's static Merge method accepts multiple documents directly, eliminating the URL-based workflow.

Password-Protected PDFs

Api2pdf Implementation:

using Api2Pdf.DotNet;

var a2pClient = new Api2PdfClient("YOUR_API_KEY");

// Generate PDF first
var pdfResponse = await a2pClient.HeadlessChrome.FromHtmlAsync("<h1>Confidential</h1>");

// Then add password protection in separate call
var protectedResponse = await a2pClient.PdfSharp.SetPasswordAsync(
    pdfResponse.Pdf,
    "secretpassword"
);
using Api2Pdf.DotNet;

var a2pClient = new Api2PdfClient("YOUR_API_KEY");

// Generate PDF first
var pdfResponse = await a2pClient.HeadlessChrome.FromHtmlAsync("<h1>Confidential</h1>");

// Then add password protection in separate call
var protectedResponse = await a2pClient.PdfSharp.SetPasswordAsync(
    pdfResponse.Pdf,
    "secretpassword"
);
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IronPDF Implementation:

using IronPdf;

var renderer = new ChromePdfRenderer();
var pdf = renderer.RenderHtmlAsPdf("<h1>Confidential</h1>");

// Set security in one step
pdf.SecuritySettings.OwnerPassword = "owner123";
pdf.SecuritySettings.UserPassword = "user123";
pdf.SecuritySettings.AllowUserPrinting = PdfPrintSecurity.NoPrint;
pdf.SecuritySettings.AllowUserCopyPasteContent = false;
pdf.SecuritySettings.AllowUserEdits = PdfEditSecurity.NoEdit;

pdf.SaveAs("protected.pdf");
using IronPdf;

var renderer = new ChromePdfRenderer();
var pdf = renderer.RenderHtmlAsPdf("<h1>Confidential</h1>");

// Set security in one step
pdf.SecuritySettings.OwnerPassword = "owner123";
pdf.SecuritySettings.UserPassword = "user123";
pdf.SecuritySettings.AllowUserPrinting = PdfPrintSecurity.NoPrint;
pdf.SecuritySettings.AllowUserCopyPasteContent = false;
pdf.SecuritySettings.AllowUserEdits = PdfEditSecurity.NoEdit;

pdf.SaveAs("protected.pdf");
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IronPDF provides granular control over PDF permissions through the SecuritySettings property.

Headers and Footers

Api2pdf Implementation:

using Api2Pdf.DotNet;

var a2pClient = new Api2PdfClient("YOUR_API_KEY");

var options = new HeadlessChromeOptions
{
    HeaderHtml = "<div style='font-size:10px'>Company Header</div>",
    FooterHtml = "<div style='font-size:10px'>Page <span class='pageNumber'></span></div>"
};

var response = await a2pClient.HeadlessChrome.FromHtmlAsync(html, options);
using Api2Pdf.DotNet;

var a2pClient = new Api2PdfClient("YOUR_API_KEY");

var options = new HeadlessChromeOptions
{
    HeaderHtml = "<div style='font-size:10px'>Company Header</div>",
    FooterHtml = "<div style='font-size:10px'>Page <span class='pageNumber'></span></div>"
};

var response = await a2pClient.HeadlessChrome.FromHtmlAsync(html, options);
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IronPDF Implementation:

using IronPdf;

var renderer = new ChromePdfRenderer();

// HTML headers and footers with full styling
renderer.RenderingOptions.HtmlHeader = new HtmlHeaderFooter
{
    HtmlFragment = "<div style='font-size:10px; text-align:center;'>Company Header</div>",
    DrawDividerLine = true
};

renderer.RenderingOptions.HtmlFooter = new HtmlHeaderFooter
{
    HtmlFragment = "<div style='font-size:10px; text-align:center;'>Page {page} of {total-pages}</div>",
    DrawDividerLine = true
};

var pdf = renderer.RenderHtmlAsPdf(html);
pdf.SaveAs("with-headers.pdf");
using IronPdf;

var renderer = new ChromePdfRenderer();

// HTML headers and footers with full styling
renderer.RenderingOptions.HtmlHeader = new HtmlHeaderFooter
{
    HtmlFragment = "<div style='font-size:10px; text-align:center;'>Company Header</div>",
    DrawDividerLine = true
};

renderer.RenderingOptions.HtmlFooter = new HtmlHeaderFooter
{
    HtmlFragment = "<div style='font-size:10px; text-align:center;'>Page {page} of {total-pages}</div>",
    DrawDividerLine = true
};

var pdf = renderer.RenderHtmlAsPdf(html);
pdf.SaveAs("with-headers.pdf");
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IronPDF supports placeholder tokens like {page} and {total-pages} for dynamic page numbering. For more options, see the headers and footers documentation.

ASP.NET Core Integration

Api2pdf's async HTTP pattern differs significantly from IronPDF's direct PDF generation.

Api2pdf Pattern:

[ApiController]
public class PdfController : ControllerBase
{
    private readonly Api2PdfClient _client;

    public PdfController()
    {
        _client = new Api2PdfClient("YOUR_API_KEY");
    }

    [HttpGet("generate")]
    public async Task<IActionResult> GeneratePdf()
    {
        var response = await _client.HeadlessChrome.FromHtmlAsync("<h1>Report</h1>");

        if (!response.Success)
            return BadRequest(response.Error);

        // Redirect to download URL
        return Redirect(response.Pdf);
    }
}
[ApiController]
public class PdfController : ControllerBase
{
    private readonly Api2PdfClient _client;

    public PdfController()
    {
        _client = new Api2PdfClient("YOUR_API_KEY");
    }

    [HttpGet("generate")]
    public async Task<IActionResult> GeneratePdf()
    {
        var response = await _client.HeadlessChrome.FromHtmlAsync("<h1>Report</h1>");

        if (!response.Success)
            return BadRequest(response.Error);

        // Redirect to download URL
        return Redirect(response.Pdf);
    }
}
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IronPDF Pattern:

[ApiController]
public class PdfController : ControllerBase
{
    [HttpGet("generate")]
    public IActionResult GeneratePdf()
    {
        var renderer = new ChromePdfRenderer();
        var pdf = renderer.RenderHtmlAsPdf("<h1>Report</h1>");

        // Return PDF directly - no download step needed
        return File(pdf.BinaryData, "application/pdf", "report.pdf");
    }

    [HttpGet("generate-async")]
    public async Task<IActionResult> GeneratePdfAsync()
    {
        var renderer = new ChromePdfRenderer();
        var pdf = await renderer.RenderHtmlAsPdfAsync("<h1>Report</h1>");

        return File(pdf.Stream, "application/pdf", "report.pdf");
    }
}
[ApiController]
public class PdfController : ControllerBase
{
    [HttpGet("generate")]
    public IActionResult GeneratePdf()
    {
        var renderer = new ChromePdfRenderer();
        var pdf = renderer.RenderHtmlAsPdf("<h1>Report</h1>");

        // Return PDF directly - no download step needed
        return File(pdf.BinaryData, "application/pdf", "report.pdf");
    }

    [HttpGet("generate-async")]
    public async Task<IActionResult> GeneratePdfAsync()
    {
        var renderer = new ChromePdfRenderer();
        var pdf = await renderer.RenderHtmlAsPdfAsync("<h1>Report</h1>");

        return File(pdf.Stream, "application/pdf", "report.pdf");
    }
}
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IronPDF returns the PDF directly via BinaryData or Stream, eliminating the redirect-to-download pattern.

Dependency Injection Configuration

// Program.cs or Startup.cs
public void ConfigureServices(IServiceCollection services)
{
    services.AddScoped<IPdfService, IronPdfService>();
}

// IPdfService.cs
public interface IPdfService
{
    PdfDocument GenerateFromHtml(string html);
    Task<PdfDocument> GenerateFromHtmlAsync(string html);
}

// IronPdfService.cs
public class IronPdfService : IPdfService
{
    private readonly ChromePdfRenderer _renderer;

    public IronPdfService()
    {
        _renderer = new ChromePdfRenderer();
        _renderer.RenderingOptions.PrintHtmlBackgrounds = true;
        _renderer.RenderingOptions.PaperSize = PdfPaperSize.A4;
    }

    public PdfDocument GenerateFromHtml(string html) =>
        _renderer.RenderHtmlAsPdf(html);

    public Task<PdfDocument> GenerateFromHtmlAsync(string html) =>
        _renderer.RenderHtmlAsPdfAsync(html);
}
// Program.cs or Startup.cs
public void ConfigureServices(IServiceCollection services)
{
    services.AddScoped<IPdfService, IronPdfService>();
}

// IPdfService.cs
public interface IPdfService
{
    PdfDocument GenerateFromHtml(string html);
    Task<PdfDocument> GenerateFromHtmlAsync(string html);
}

// IronPdfService.cs
public class IronPdfService : IPdfService
{
    private readonly ChromePdfRenderer _renderer;

    public IronPdfService()
    {
        _renderer = new ChromePdfRenderer();
        _renderer.RenderingOptions.PrintHtmlBackgrounds = true;
        _renderer.RenderingOptions.PaperSize = PdfPaperSize.A4;
    }

    public PdfDocument GenerateFromHtml(string html) =>
        _renderer.RenderHtmlAsPdf(html);

    public Task<PdfDocument> GenerateFromHtmlAsync(string html) =>
        _renderer.RenderHtmlAsPdfAsync(html);
}
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Error Handling Migration

Api2pdf uses response object checks. IronPDF uses standard .NET exceptions.

Api2pdf Pattern:

var response = await a2pClient.HeadlessChrome.FromHtmlAsync(html);

if (!response.Success)
{
    Console.WriteLine($"Error: {response.Error}");
    return;
}
var response = await a2pClient.HeadlessChrome.FromHtmlAsync(html);

if (!response.Success)
{
    Console.WriteLine($"Error: {response.Error}");
    return;
}
$vbLabelText   $csharpLabel

IronPDF Pattern:

try
{
    var renderer = new ChromePdfRenderer();
    var pdf = renderer.RenderHtmlAsPdf(html);
    pdf.SaveAs("output.pdf");
}
catch (IronPdf.Exceptions.IronPdfLicenseException ex)
{
    Console.WriteLine($"License error: {ex.Message}");
}
catch (IronPdf.Exceptions.IronPdfRenderingException ex)
{
    Console.WriteLine($"Rendering error: {ex.Message}");
}
catch (Exception ex)
{
    Console.WriteLine($"Error: {ex.Message}");
}
try
{
    var renderer = new ChromePdfRenderer();
    var pdf = renderer.RenderHtmlAsPdf(html);
    pdf.SaveAs("output.pdf");
}
catch (IronPdf.Exceptions.IronPdfLicenseException ex)
{
    Console.WriteLine($"License error: {ex.Message}");
}
catch (IronPdf.Exceptions.IronPdfRenderingException ex)
{
    Console.WriteLine($"Rendering error: {ex.Message}");
}
catch (Exception ex)
{
    Console.WriteLine($"Error: {ex.Message}");
}
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Performance Comparison

MetricApi2pdfIronPDF
Simple HTML2-5 seconds (network)100-500ms (local)
Complex page5-10 seconds500ms-2s
Batch of 100Minutes (rate limits)Seconds (parallel)
OfflineNot availableWorks fully
Cold startNone~2s (first render)

Performance Optimization Tips

// 1. Reuse renderer instance
private static readonly ChromePdfRenderer SharedRenderer = new ChromePdfRenderer();

public PdfDocument GeneratePdf(string html)
{
    return SharedRenderer.RenderHtmlAsPdf(html);
}

// 2. Parallel generation
var tasks = htmlDocs.Select(html =>
    Task.Run(() => SharedRenderer.RenderHtmlAsPdf(html)));
var results = await Task.WhenAll(tasks);

// 3. Disable unnecessary features for speed
var renderer = new ChromePdfRenderer();
renderer.RenderingOptions.EnableJavaScript = false; // If not needed
renderer.RenderingOptions.WaitFor.RenderDelay(0);   // No delay
// 1. Reuse renderer instance
private static readonly ChromePdfRenderer SharedRenderer = new ChromePdfRenderer();

public PdfDocument GeneratePdf(string html)
{
    return SharedRenderer.RenderHtmlAsPdf(html);
}

// 2. Parallel generation
var tasks = htmlDocs.Select(html =>
    Task.Run(() => SharedRenderer.RenderHtmlAsPdf(html)));
var results = await Task.WhenAll(tasks);

// 3. Disable unnecessary features for speed
var renderer = new ChromePdfRenderer();
renderer.RenderingOptions.EnableJavaScript = false; // If not needed
renderer.RenderingOptions.WaitFor.RenderDelay(0);   // No delay
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Troubleshooting Common Migration Issues

Issue: PDF Looks Different from Api2pdf Output

Match Api2pdf's Headless Chrome settings:

var renderer = new ChromePdfRenderer();
renderer.RenderingOptions.CssMediaType = PdfCssMediaType.Print;
renderer.RenderingOptions.PrintHtmlBackgrounds = true;
renderer.RenderingOptions.ViewPortWidth = 1280;
renderer.RenderingOptions.EnableJavaScript = true;
renderer.RenderingOptions.WaitFor.RenderDelay(1000);
var renderer = new ChromePdfRenderer();
renderer.RenderingOptions.CssMediaType = PdfCssMediaType.Print;
renderer.RenderingOptions.PrintHtmlBackgrounds = true;
renderer.RenderingOptions.ViewPortWidth = 1280;
renderer.RenderingOptions.EnableJavaScript = true;
renderer.RenderingOptions.WaitFor.RenderDelay(1000);
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Issue: External Resources Not Loading

Configure resource loading timeouts:

var renderer = new ChromePdfRenderer();
renderer.RenderingOptions.WaitFor.AllFontsLoaded(timeout: 10000);
renderer.RenderingOptions.WaitFor.NetworkIdle(timeout: 10000);

// Or use base URL for relative paths
var pdf = renderer.RenderHtmlAsPdf(html, baseUrl: "https://example.com/");
var renderer = new ChromePdfRenderer();
renderer.RenderingOptions.WaitFor.AllFontsLoaded(timeout: 10000);
renderer.RenderingOptions.WaitFor.NetworkIdle(timeout: 10000);

// Or use base URL for relative paths
var pdf = renderer.RenderHtmlAsPdf(html, baseUrl: "https://example.com/");
$vbLabelText   $csharpLabel

Issue: Large PDF File Sizes

Compress images after generation:

renderer.RenderingOptions.ImageQuality = 80;

// Or compress after generation
pdf.CompressImages(quality: 75);
pdf.SaveAs("compressed.pdf");
renderer.RenderingOptions.ImageQuality = 80;

// Or compress after generation
pdf.CompressImages(quality: 75);
pdf.SaveAs("compressed.pdf");
$vbLabelText   $csharpLabel

Post-Migration Checklist

After completing the code migration, verify the following:

  • Verify PDF output quality matches expectations
  • Test all edge cases (large documents, special characters)
  • Validate performance metrics (should see significant improvement)
  • Update Docker configurations if applicable
  • Remove Api2pdf portal account and API keys
  • Update monitoring (no more API latency tracking needed)
  • Document new patterns for your team
  • Update CI/CD pipelines

Future-Proofing Your PDF Infrastructure

With .NET 10 approaching and C# 14 introducing new language features, choosing a native .NET PDF library ensures compatibility with evolving runtime capabilities. IronPDF's commitment to supporting the latest .NET versions means your migration investment pays dividends as projects extend into 2025 and 2026—without ongoing per-conversion costs accumulating.

Additional Resources

Migrating from Api2pdf to IronPDF transforms your PDF generation from a cloud-dependent, per-conversion cost model to a local, one-time investment. Your sensitive documents stay on your infrastructure, latency drops from seconds to milliseconds, and you eliminate vendor dependency for this critical application capability.

Curtis Chau
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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