HtmlToPdf.AspNetCore 1.1.0

HtmlToPdf.AspNetCore

A fast, accurate HTML to PDF conversion library for .NET with perfect RTL (Right-to-Left) language support. Built on Chromium for pixel-perfect rendering with full Arabic, Urdu, Persian, and Hebrew text support.

✨ Features

• 🌍 Perfect RTL Support - Native support for Arabic, Urdu, Persian, Hebrew and other RTL languages
• ⚡ Fast Performance - Optimized for high-throughput PDF generation
• 🎯 Pixel-Perfect Rendering - Chromium-based rendering with full CSS3, JavaScript, and web font support
• 🔧 Simple API - Easy to use with just one line of code
• 🚀 Automatic Browser Management - Auto-downloads Chromium if not installed
• 📱 Cross-Platform - Works on Windows, Linux, and macOS
• 🔒 Thread-Safe - Safe for concurrent use in web applications
• ✍️ Document Signing - Add signatures, stamps, and watermarks to your PDFs
• 🖼️ Image Signatures - Support for image-based signatures (PNG, JPG, etc.)
• 🔏 Digital Stamps - Create official-looking stamps and seals
• 💧 Watermarks - Add transparent watermarks (DRAFT, CONFIDENTIAL, etc.)

📦 Installation

Using .NET CLI

dotnet add package HtmlToPdf.AspNetCore

Using Package Manager

Install-Package HtmlToPdf.AspNetCore

🚀 Quick Start

Basic Usage

using HtmlToPdf.AspNetCore;

var html = "<h1>Hello World</h1><p>This is a simple PDF document.</p>";
byte[] pdf = Pdf.Render(html);

File.WriteAllBytes("output.pdf", pdf);

ASP.NET Core Controller Example

using HtmlToPdf.AspNetCore;
using Microsoft.AspNetCore.Mvc;

[ApiController]
[Route("api/pdf")]
public class PdfController : ControllerBase
{
    [HttpPost]
    public IActionResult GeneratePdf([FromBody] string html)
    {
        byte[] pdfBytes = Pdf.Render(html);
        return File(pdfBytes, "application/pdf", "document.pdf");
    }
}

🌍 RTL Language Support

Arabic Example

var arabicHtml = @"
<div dir='rtl' style='font-family: Arial, sans-serif; text-align: right;'>
    <h1>التقرير الشهري</h1>
    <p>هذا تقرير يحتوي على نص باللغة العربية مع دعم كامل للتشكيل والاتجاه من اليمين لليسار.</p>
</div>";

byte[] arabicPdf = Pdf.Render(arabicHtml, new PdfOptions
{
    Language = PdfLanguage.Arabic,
    MarginMm = 20
});

Urdu Example

var urduHtml = @"
<div dir='rtl' style='font-family: Jameel Noori Nastaleeq;'>
    <h1>رپورٹ</h1>
    <p>یہ اردو زبان میں لکھی گئی ایک رپورٹ ہے جو کامل طور پر دائیں سے بائیں کی طرف چلتی ہے۔</p>
</div>";

byte[] urduPdf = Pdf.Render(urduHtml, new PdfOptions
{
    Language = PdfLanguage.Urdu,
    PageSize = PageSize.A5
});

Hebrew Example

var hebrewHtml = @"
<div dir='rtl' style='font-family: David, Arial Hebrew;'>
    <h1>דוח חודשי</h1>
    <p>זהו דוח בעברית המדגים תמיכה מלאה בכתיבה מימין לשמאל.</p>
</div>";

byte[] hebrewPdf = Pdf.Render(hebrewHtml, new PdfOptions
{
    Language = PdfLanguage.Hebrew,
    MarginMm = 15
});

🔀 Mixed RTL / LTR Content

var mixedHtml = @"
<div>
    <p><span dir='rtl'>هذا النص بالعربية</span> contains 
    <span dir='ltr'>English text</span> and 
    <span dir='rtl'>المزيد من العربية</span></p>

    <p><span dir='ltr'>Product Code: INV-2024-001</span> - 
    <span dir='rtl'>رمز المنتج</span></p>
</div>";

byte[] mixedPdf = Pdf.Render(mixedHtml);

✍️ Document Signing

Text Signatures

string html = @"
<div class='signature-box'>
<p><strong>Signed by:</strong> John Doe</p>
<p><strong>Date:</strong> " + DateTime.Now.ToString("yyyy-MM-dd") + @"</p>
<div class='signature-line'>John Doe</div>
</div>";

byte[] pdf = Pdf.Render(html);

Image Signatures

byte[] signatureImageBytes = File.ReadAllBytes("signature.png");
string signatureBase64 = Convert.ToBase64String(signatureImageBytes);

string html = $@"
<img src='data:image/png;base64,{signatureBase64}' style='max-width:200px;'/>";

byte[] pdf = Pdf.Render(html);

Multiple Signatures

byte[] sig1 = File.ReadAllBytes("signature1.png");
byte[] sig2 = File.ReadAllBytes("signature2.png");

string html = $@"
<img src='data:image/png;base64,{Convert.ToBase64String(sig1)}'/>
<img src='data:image/png;base64,{Convert.ToBase64String(sig2)}'/>
";

byte[] pdf = Pdf.Render(html);

🔏 Stamps and Seals

<div class="stamp">
APPROVED
<br/>
2026-03-12
</div>

.stamp {
border:3px solid red;
border-radius:50%;
width:150px;
height:150px;
text-align:center;
font-weight:bold;
transform:rotate(-15deg);
}

💧 Watermarks

<div class="watermark">CONFIDENTIAL</div>

.watermark{
position:fixed;
top:50%;
left:50%;
transform:translate(-50%,-50%) rotate(-45deg);
font-size:72px;
opacity:0.2;
}

⚙️ Configuration Options

var options = new PdfOptions
{
    PageSize = PageSize.A4,
    Landscape = false,
    MarginMm = 15,

    Language = PdfLanguage.Auto,
    Scale = 1.0f,
    PrintBackground = true,

    TimeoutMs = 7000
};

📄 Page Size Options

public enum PageSize
{
    A4,
    Letter,
    Legal,
    A3,
    A5
}

🌐 Language Options

public enum PdfLanguage
{
    Auto,
    Arabic,
    Urdu,
    English,
    Hebrew
}

📋 Requirements

Runtime

• .NET 10.0

Supported Browsers

One of the following must be available:

• Google Chrome
• Microsoft Edge
• Chromium

If no browser is detected, the library will automatically download Chromium (~200MB).

🎯 Performance Tips

• Cache generated PDFs for identical HTML
• Use inline CSS instead of external stylesheets
• Compress large images before embedding
• Increase TimeoutMs for complex JavaScript pages

🔒 Error Handling

try
{
    byte[] pdf = Pdf.Render(html);
}
catch (HtmlToPdfException ex)
{
    Console.WriteLine($"PDF generation failed: {ex.Message}");
}
catch (Exception ex)
{
    Console.WriteLine($"Unexpected error: {ex.Message}");
}

🐛 Troubleshooting

Browser not found

• Install Chrome / Edge / Chromium
• Allow internet access for auto download

RTL text issues

• Use dir="rtl"
• Set proper fonts
• Specify Language in PdfOptions

Watermarks not visible

• Use position: fixed
• Increase z-index

📝 License

MIT License

❤️ Author

Muammar Siddiqui