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How to Convert PDF to HTML in C# (Developer Guide)

#dotnet #csharp

Converting PDF to HTML extracts content for web display, analysis, or further processing. Useful for debugging PDF layouts, migrating content to web formats, or making PDFs searchable.

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

var pdf = PdfDocument.FromFile("document.pdf");
pdf.SaveAsHtml("output.html");
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IronPDF converts PDFs to valid HTML that renders in any browser.

How Do I Convert PDF to HTML String?

Get HTML as a string for processing:

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

var pdf = PdfDocument.FromFile("report.pdf");

// Get HTML as string
string html = pdf.ToHtmlString();

// Analyze content
Console.WriteLine($"HTML length: {html.Length} characters");
Console.WriteLine(html.Substring(0, 500)); // Preview first 500 chars
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The string can be manipulated, searched, or stored in databases.

How Do I Save PDF as HTML File?

Write directly to file:

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

var pdf = PdfDocument.FromFile("annual-report.pdf");

// Save as HTML file
pdf.SaveAsHtml("annual-report.html");

Console.WriteLine("Converted successfully");
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The output HTML file can be opened in any web browser.

What Does the Output HTML Look Like?

IronPDF generates SVG-based HTML that preserves layout:

<!DOCTYPE html>
<html>
<head>
    <style>
        /* Embedded styles for layout */
    </style>
</head>
<body>
    <svg>
        <!-- Vector graphics representing PDF content -->
        <text x="100" y="50">Document Title</text>
        <text x="100" y="80">Content paragraph...</text>
    </svg>
</body>
</html>
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The SVG format preserves exact positioning and fonts from the original PDF.

How Do I Extract Text from the HTML?

Parse the converted HTML for text content:

using IronPdf;
using System.Text.RegularExpressions;
// Install via NuGet: Install-Package IronPdf

var pdf = PdfDocument.FromFile("document.pdf");
string html = pdf.ToHtmlString();

// Strip HTML tags to get plain text
string plainText = Regex.Replace(html, "<[^>]+>", " ");
plainText = Regex.Replace(plainText, @"\s+", " ").Trim();

Console.WriteLine(plainText);
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Or use IronPDF's built-in text extraction:

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

var pdf = PdfDocument.FromFile("document.pdf");

// Direct text extraction (simpler)
string text = pdf.ExtractAllText();
Console.WriteLine(text);
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How Do I Convert Multiple PDFs?

Batch conversion for document migration:

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

public void BatchConvertToHtml(string inputFolder, string outputFolder)
{
    var files = Directory.GetFiles(inputFolder, "*.pdf");

    foreach (var file in files)
    {
        var pdf = PdfDocument.FromFile(file);

        var baseName = Path.GetFileNameWithoutExtension(file);
        var outputPath = Path.Combine(outputFolder, $"{baseName}.html");

        pdf.SaveAsHtml(outputPath);
        pdf.Dispose();

        Console.WriteLine($"Converted: {baseName}");
    }

    Console.WriteLine($"Converted {files.Length} files");
}

// Usage
BatchConvertToHtml("C:/Documents/PDFs", "C:/Documents/HTML");
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How Do I Compare PDF Content?

Use HTML conversion for content analysis:

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

public bool ComparePdfContent(string pdfPath1, string pdfPath2)
{
    var pdf1 = PdfDocument.FromFile(pdfPath1);
    var pdf2 = PdfDocument.FromFile(pdfPath2);

    string html1 = pdf1.ToHtmlString();
    string html2 = pdf2.ToHtmlString();

    // Simple comparison
    bool identical = html1 == html2;

    // Or extract text for semantic comparison
    string text1 = pdf1.ExtractAllText();
    string text2 = pdf2.ExtractAllText();

    return text1.Trim() == text2.Trim();
}
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How Do I Handle Multi-Page PDFs?

Each page converts with its content:

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

var pdf = PdfDocument.FromFile("multipage-report.pdf");

// Convert entire document
pdf.SaveAsHtml("full-report.html");

// Or convert specific pages
for (int i = 0; i < pdf.PageCount; i++)
{
    var singlePage = pdf.CopyPage(i);
    singlePage.SaveAsHtml($"page-{i + 1}.html");
    singlePage.Dispose();
}
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How Do I Convert for Web Display?

Embed converted content in web pages:

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

public string GetPdfAsHtmlFragment(string pdfPath)
{
    var pdf = PdfDocument.FromFile(pdfPath);
    string html = pdf.ToHtmlString();

    // Extract body content only (skip DOCTYPE and html tags)
    int bodyStart = html.IndexOf("<body");
    int bodyEnd = html.LastIndexOf("</body>") + 7;

    if (bodyStart >= 0 && bodyEnd > bodyStart)
    {
        return html.Substring(bodyStart, bodyEnd - bodyStart);
    }

    return html;
}
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Use in ASP.NET:

public IActionResult ViewPdf(string filename)
{
    var pdf = PdfDocument.FromFile($"pdfs/{filename}");
    string html = pdf.ToHtmlString();

    return Content(html, "text/html");
}
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How Do I Debug PDF Layout Issues?

Analyze HTML structure to understand PDF problems:

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

public void AnalyzePdfStructure(string pdfPath)
{
    var pdf = PdfDocument.FromFile(pdfPath);
    string html = pdf.ToHtmlString();

    // Count text elements
    int textCount = Regex.Matches(html, "<text").Count;

    // Find all style definitions
    var styleMatches = Regex.Matches(html, @"style=""([^""]+)""");

    Console.WriteLine($"Text elements: {textCount}");
    Console.WriteLine($"Style definitions: {styleMatches.Count}");

    // Check for specific content
    if (html.Contains("font-family"))
    {
        Console.WriteLine("Custom fonts detected");
    }

    // Page dimensions
    var svgMatch = Regex.Match(html, @"viewBox=""([^""]+)""");
    if (svgMatch.Success)
    {
        Console.WriteLine($"Viewport: {svgMatch.Groups[1].Value}");
    }
}
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How Do I Convert Password-Protected PDFs?

Handle encrypted documents:

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

var pdf = PdfDocument.FromFile("secured.pdf", "password123");
pdf.SaveAsHtml("decrypted-content.html");
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You need the correct password to convert protected PDFs.

How Do I Preserve Images?

Images are embedded in the HTML output:

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

var pdf = PdfDocument.FromFile("brochure.pdf");
pdf.SaveAsHtml("brochure.html");

// Images are typically embedded as base64 or SVG
// The output HTML is self-contained
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The generated HTML includes all images—no external references needed.

When Should I Use PDF to HTML?

Use Case Benefit
Content migration Move PDF content to web
Search indexing Make PDFs searchable
Layout debugging Understand PDF structure
Content comparison Diff two versions
Accessibility Convert for screen readers
Text extraction Get raw content

Quick Reference

Method Purpose
pdf.ToHtmlString() Get HTML as string
pdf.SaveAsHtml(path) Save to HTML file
pdf.ExtractAllText() Get plain text only
pdf.CopyPage(i) Extract single page

PDF to HTML conversion makes PDF content accessible for web applications and content processing workflows.

For more conversion options, see the IronPDF PDF to HTML documentation.

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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