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iTextsharp HTML to PDF in C# Alternatives

#csharp #dotnet

If you've tried using iTextSharp for HTML-to-PDF conversion, you've probably experienced the pain: broken layouts, missing CSS, unsupported modern features, and verbose, complex APIs.

iTextSharp wasn't designed for HTML rendering. It's a low-level PDF manipulation library that happens to have an outdated HTML parser bolted on.

Here's why iTextSharp fails at HTML-to-PDF, and what to use instead in 2025.

Why iTextSharp Fails at HTML-to-PDF

1. Requires Paid Add-On (pdfHTML)

iTextSharp's core library doesn't support HTML at all. For HTML-to-PDF conversion, you need pdfHTML, a paid commercial add-on.

Pricing:

  • iTextSharp Core (AGPL): "Free" but requires open-sourcing your app
  • pdfHTML Add-On: Requires commercial license ($1,800+ per developer)

So "free" iTextSharp actually costs more than alternatives like IronPDF ($749).

2. Outdated HTML/CSS Support

pdfHTML's rendering engine is years behind modern web standards.

What doesn't work:

❌ Flexbox (Bootstrap 4/5 layouts break)
❌ CSS Grid (modern responsive layouts fail)
❌ CSS Variables (custom properties ignored)
❌ Modern selectors (:nth-child, :not, attribute selectors)
❌ JavaScript (no execution before rendering)
❌ Web fonts (Google Fonts often fail to load)

Example that breaks in iTextSharp:

<div style="display: flex; justify-content: space-between;">
    <div>Left column</div>
    <div>Right column</div>
</div>
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iTextSharp result: Columns stack vertically instead of side-by-side (flexbox not supported).

IronPDF result: Perfect side-by-side layout (Chromium rendering).

3. Incredibly Verbose API

Simple HTML conversion requires dozens of lines of boilerplate code.

iTextSharp HTML to PDF:

using iText.Html2Pdf;
using iText.Kernel.Pdf;
using System.IO;
// Requires commercial pdfHTML add-on

var html = "<h1>Hello World</h1>";
var htmlStream = new MemoryStream(System.Text.Encoding.UTF8.GetBytes(html));

using var pdfStream = new FileStream("output.pdf", FileMode.Create);
using var pdfWriter = new PdfWriter(pdfStream);
using var pdfDocument = new PdfDocument(pdfWriter);

HtmlConverter.ConvertToPdf(htmlStream, pdfDocument);
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IronPDF equivalent:

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

var renderer = new [ChromePdfRenderer](https://ironpdf.com/blog/videos/how-to-render-webgl-sites-to-pdf-in-csharp-ironpdf/)();
var pdf = renderer.RenderHtmlAsPdf("<h1>Hello World</h1>");
pdf.SaveAs("output.pdf");
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80% less code, same result.

4. Bootstrap Layouts Break

Bootstrap relies heavily on flexbox (since Bootstrap 4). iTextSharp's pdfHTML doesn't support flexbox, so layouts break completely.

Bootstrap HTML:

<link href="https://cdn.jsdelivr.net/npm/bootstrap@5.3.0/dist/css/bootstrap.min.css" rel="stylesheet">
<div class="container">
    <div class="row">
        <div class="col">Column 1</div>
        <div class="col">Column 2</div>
        <div class="col">Column 3</div>
    </div>
</div>
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iTextSharp result: Three rows (stacked vertically) instead of three columns.

IronPDF result: Three side-by-side columns (Chromium understands Bootstrap).

5. JavaScript Doesn't Execute

If your HTML relies on JavaScript to populate content (charts, SPAs, dynamic data), iTextSharp renders an empty PDF.

HTML with JavaScript:

<div id="content">Loading...</div>
<script>
    document.getElementById('content').innerHTML = '<h1>Loaded!</h1>';
</script>
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iTextSharp result: PDF shows "Loading..." (JavaScript never executed).

IronPDF result: PDF shows "Loaded!" (Chromium executes JavaScript first).

6. Poor Documentation

iTextSharp's documentation is fragmented across:

  • Stack Overflow (outdated answers)
  • Official docs (often for Java version, not C#)
  • GitHub issues (no official support)

Finding solutions requires:

  • Searching multiple sources
  • Trial and error
  • Reading source code

IronPDF's documentation is comprehensive, C#-focused, and includes working code examples for every feature.

Better Alternative #1: IronPDF (Chromium-Based)

IronPDF uses Chromium rendering (same engine as Google Chrome), which means:

✅ Full HTML5/CSS3 support (flexbox, grid, variables)
✅ JavaScript execution (charts, SPAs, dynamic content)
✅ Bootstrap/Tailwind work perfectly
✅ Google Fonts and custom fonts load reliably
✅ Simpler API (3 lines vs. 20+ lines)

IronPDF HTML-to-PDF:

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

var html = @"
<link href='https://cdn.jsdelivr.net/npm/bootstrap@5.3.0/dist/css/bootstrap.min.css' rel='stylesheet'>
<div class='container'>
    <div class='row'>
        <div class='col'>Column 1</div>
        <div class='col'>Column 2</div>
        <div class='col'>Column 3</div>
    </div>
</div>";

var renderer = new ChromePdfRenderer();
var pdf = renderer.RenderHtmlAsPdf(html);
pdf.SaveAs("bootstrap.pdf");
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Result: Perfect 3-column layout.

Pricing: $749 per developer (cheaper than iTextSharp + pdfHTML commercial license).

Better Alternative #2: PuppeteerSharp (Headless Chrome)

PuppeteerSharp is a .NET port of Google's Puppeteer (browser automation).

Pros:

  • Free (Apache 2.0 license)
  • Chromium-based (modern rendering)
  • Supports JavaScript execution

Cons:

  • Large (300MB+ Chromium binaries)
  • Resource-intensive (spawns browser processes)
  • Not a PDF library (it's a testing tool)

PuppeteerSharp HTML-to-PDF:

using PuppeteerSharp;
// Install via NuGet: Install-Package PuppeteerSharp

var browser = await Puppeteer.LaunchAsync(new LaunchOptions { Headless = true });
var page = await browser.NewPageAsync();
await page.SetContentAsync("<h1>Hello World</h1>");
await page.PdfAsync("output.pdf");
await browser.CloseAsync();
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Good for: Projects with $0 budget that can tolerate complexity.

Not good for: Production apps requiring simple deployment.

Better Alternative #3: Playwright for .NET

Playwright is Microsoft's browser automation library (similar to Puppeteer).

Pros:

  • Free (Apache 2.0)
  • Modern Chromium rendering
  • Cross-browser support (Chromium, Firefox, WebKit)

Cons:

  • Heavy (browser binaries)
  • Complex deployment
  • Not a PDF library (testing tool)

Playwright HTML-to-PDF:

using Microsoft.Playwright;
// Install via NuGet: Install-Package Microsoft.Playwright

var playwright = await Playwright.CreateAsync();
var browser = await playwright.Chromium.LaunchAsync();
var page = await browser.NewPageAsync();
await page.SetContentAsync("<h1>Hello World</h1>");
await page.PdfAsync(new() { Path = "output.pdf" });
await browser.CloseAsync();
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Good for: Teams already using Playwright for testing.

Not good for: Dedicated PDF generation.

Comparison: iTextSharp vs. Alternatives

Feature iTextSharp + pdfHTML IronPDF PuppeteerSharp Playwright
HTML5/CSS3 Support ❌ Limited ✅ Full (Chromium) ✅ Full ✅ Full
Flexbox/Grid ❌ No ✅ Yes ✅ Yes ✅ Yes
JavaScript Execution ❌ No ✅ Yes ✅ Yes ✅ Yes
Bootstrap Layouts ❌ Breaks ✅ Works ✅ Works ✅ Works
API Simplicity ❌ Verbose ✅ Simple ⚠️ Moderate ⚠️ Moderate
Deployment Size Small Medium Large (300MB+) Large (300MB+)
Licensing AGPL or $1,800+ $749 Free (Apache 2.0) Free (Apache 2.0)
PDF Manipulation ✅ Excellent ✅ Yes ❌ No ❌ No

Migration: iTextSharp to IronPDF

Before (iTextSharp) 

using iText.Html2Pdf;
using iText.Kernel.Pdf;
// Requires commercial pdfHTML license

var htmlContent = "<h1>Invoice #12345</h1><p>Total: $500</p>";
var htmlStream = new MemoryStream(System.Text.Encoding.UTF8.GetBytes(htmlContent));

using var pdfStream = new FileStream("invoice.pdf", FileMode.Create);
using var pdfWriter = new PdfWriter(pdfStream);
using var pdfDocument = new PdfDocument(pdfWriter);

HtmlConverter.ConvertToPdf(htmlStream, pdfDocument);
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After (IronPDF) 

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

var htmlContent = "<h1>Invoice #12345</h1><p>Total: $500</p>";

var renderer = new ChromePdfRenderer();
var pdf = renderer.RenderHtmlAsPdf(htmlContent);
pdf.SaveAs("invoice.pdf");
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Benefits:

  • 70% less code
  • Modern CSS support
  • No stream management
  • Clearer intent

Real-World Example: Invoice with Bootstrap

HTML template:

<!DOCTYPE html>
<html>
<head>
    <link href="https://cdn.jsdelivr.net/npm/bootstrap@5.3.0/dist/css/bootstrap.min.css" rel="stylesheet">
</head>
<body>
    <div class="container mt-5">
        <div class="row">
            <div class="col">
                <h1>Invoice #12345</h1>
                <p>Date: January 26, 2025</p>
            </div>
            <div class="col text-end">
                <img src="logo.png" alt="Company Logo" width="150">
            </div>
        </div>

        <table class="table table-striped mt-4">
            <thead>
                <tr>
                    <th>Item</th>
                    <th>Quantity</th>
                    <th>Price</th>
                    <th>Total</th>
                </tr>
            </thead>
            <tbody>
                <tr>
                    <td>Consulting Services</td>
                    <td>10 hours</td>
                    <td>$150</td>
                    <td>$1,500</td>
                </tr>
            </tbody>
        </table>

        <div class="row mt-4">
            <div class="col text-end">
                <h3>Total: $1,500</h3>
            </div>
        </div>
    </div>
</body>
</html>
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iTextSharp result: Layout broken, columns stack, table formatting lost.

IronPDF result: Perfect professional invoice, exactly as designed.

Code:

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

var renderer = new ChromePdfRenderer();
var pdf = renderer.RenderHtmlFileAsPdf("invoice-template.html");
pdf.SaveAs("invoice.pdf");
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When to Use Each Alternative

Use IronPDF if:

  • ✅ You need modern CSS/JavaScript support
  • ✅ You're building commercial applications
  • ✅ Simple APIs matter
  • ✅ PDF manipulation features are valuable
  • ✅ Budget allows $749 per developer

Use PuppeteerSharp/Playwright if:

  • ✅ Budget is $0
  • ✅ You're okay with deployment complexity
  • ✅ You're already using them for testing
  • ✅ You don't need PDF manipulation

Avoid iTextSharp if:

  • ❌ You need HTML-to-PDF conversion (it's terrible at this)
  • ❌ You use modern CSS frameworks (Bootstrap, Tailwind)
  • ❌ You need JavaScript execution
  • ❌ Simple APIs matter

Use iTextSharp only if:

  • ✅ You need low-level PDF manipulation (not HTML conversion)
  • ✅ You're doing programmatic PDF generation (no HTML)
  • ✅ You need granular control over PDF structure

The Bottom Line

iTextSharp is terrible for HTML-to-PDF because:

  1. No HTML support in core library (requires paid add-on)
  2. Outdated CSS support (no flexbox, grid, modern features)
  3. No JavaScript execution (SPAs, charts fail)
  4. Verbose, complex API (20+ lines for simple conversions)
  5. Expensive ($1,800+ per developer with pdfHTML)

In 2025, better alternatives exist:

Use Case Best Choice Why
Production HTML-to-PDF IronPDF Modern rendering, simple API, $749
$0 budget PuppeteerSharp Free, Chromium-based, complex deployment
Already using testing tools Playwright Free, cross-browser, heavyweight
Low-level PDF manipulation iTextSharp Powerful, but NOT for HTML

Stop using iTextSharp for HTML-to-PDF in 2025. It's outdated, expensive, and broken.

Written by Jacob Mellor, CTO at Iron Software. Jacob created IronPDF and leads a team of 50+ engineers building .NET document processing libraries.

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