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How to Convert RTF to PDF in C#

#dotnet #csharp

Rich Text Format files still appear in enterprise systems—legacy documents, exported reports, and WordPad outputs. Converting them to PDF ensures consistent viewing across any platform without requiring RTF-capable software.

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

var pdf = PdfDocument.RenderRtfFileAsPdf("document.rtf");
pdf.SaveAs("document.pdf");
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Two lines. The RTF formatting—fonts, styles, colors—transfers to the PDF.

What Is RTF and Why Convert It?

RTF (Rich Text Format) is Microsoft's interchange format from the 1980s. It's:

  • Cross-platform compatible — Opens in WordPad, TextEdit, LibreOffice
  • Human-readable — Plain text with embedded formatting codes
  • Legacy-friendly — Common in older enterprise systems

But RTF has limitations:

  • Inconsistent rendering across viewers
  • No security features (encryption, permissions)
  • Large file sizes for complex documents
  • Not web-friendly

PDF solves all these. Convert once, view anywhere identically.

How Do I Convert an RTF File?

Direct file conversion:

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

// Single file conversion
var pdf = PdfDocument.RenderRtfFileAsPdf("report.rtf");
pdf.SaveAs("report.pdf");

// With full path
var pdf2 = PdfDocument.RenderRtfFileAsPdf(@"C:\documents\legacy\memo.rtf");
pdf2.SaveAs(@"C:\documents\converted\memo.pdf");
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The method reads the RTF, parses formatting codes, and generates a PDF preserving the visual layout.

How Do I Convert an RTF String?

When RTF content comes from a database or API:

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

// RTF content from database field, API response, etc.
string rtfContent = @"{\rtf1\ansi\deff0
{\fonttbl{\f0 Arial;}}
\f0\fs24 Hello, this is \b bold\b0  and \i italic\i0  text.
\par This is a new paragraph.
}";

var pdf = PdfDocument.RenderRtfStringAsPdf(rtfContent);
pdf.SaveAs("from-string.pdf");
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RTF strings include the formatting markup. IronPDF interprets it all.

How Do I Batch Convert Multiple RTF Files?

Process entire directories:

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

var rtfFiles = Directory.GetFiles(@"C:\legacy-documents", "*.rtf");

foreach (var rtfFile in rtfFiles)
{
    var outputPath = Path.ChangeExtension(rtfFile, ".pdf");
    var pdf = PdfDocument.RenderRtfFileAsPdf(rtfFile);
    pdf.SaveAs(outputPath);
    pdf.Dispose();

    Console.WriteLine($"Converted: {Path.GetFileName(rtfFile)}");
}
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Mass migration of legacy documents becomes straightforward.

How Do I Preserve RTF Formatting?

RTF supports various text styles. Here's what transfers to PDF:

RTF Feature PDF Result
Bold, italic, underline Preserved
Font face and size Preserved
Text colors Preserved
Paragraph alignment Preserved
Line spacing Preserved
Bullet lists Preserved
Tables Preserved
Embedded images Preserved

Complex formatting renders faithfully in the PDF output.

How Do I Handle Large RTF Documents?

For documents with many pages:

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

// Convert large document
var pdf = PdfDocument.RenderRtfFileAsPdf("large-manual.rtf");

// Add [page numbers](https://ironpdf.com/blog/compare-to-other-components/questpdf-add-page-number-to-pdf/) to help navigation
pdf.AddHtmlFooters(new HtmlHeaderFooter
{
    HtmlFragment = "<div style='text-align:center'>Page {page} of {total-pages}</div>"
});

// Compress for smaller file size
pdf.CompressImages(60);

pdf.SaveAs("large-manual.pdf");
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Large conversions may take a moment, but the result is a compact, navigable PDF.

How Do I Add Security to Converted PDFs?

RTF files have no security. Add protection during conversion:

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

var pdf = PdfDocument.RenderRtfFileAsPdf("confidential.rtf");

// Set passwords and permissions
pdf.SecuritySettings.OwnerPassword = "admin123";
pdf.SecuritySettings.UserPassword = "reader456";
pdf.SecuritySettings.AllowUserPrinting = PdfPrintSecurity.FullPrintRights;
pdf.SecuritySettings.AllowUserCopyPasteContent = false;
pdf.SecuritySettings.AllowUserEdits = PdfEditSecurity.NoEdit;

pdf.SaveAs("confidential-secured.pdf");
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Now your legacy document has enterprise-grade protection.

How Do I Combine Multiple RTF Files into One PDF?

Merge legacy documents:

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

var rtfFiles = new[] { "chapter1.rtf", "chapter2.rtf", "chapter3.rtf" };
var pdfs = new List<PdfDocument>();

foreach (var rtfFile in rtfFiles)
{
    pdfs.Add(PdfDocument.RenderRtfFileAsPdf(rtfFile));
}

var merged = PdfDocument.Merge(pdfs);
merged.SaveAs("complete-manual.pdf");

// Cleanup
foreach (var pdf in pdfs) pdf.Dispose();
merged.Dispose();
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Multiple RTF sources become a single cohesive PDF document.

How Do I Add Headers and Footers?

Enhance converted documents with consistent branding:

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

var pdf = PdfDocument.RenderRtfFileAsPdf("legacy-report.rtf");

// Add header
pdf.AddHtmlHeaders(new HtmlHeaderFooter
{
    HtmlFragment = @"
        <div style='text-align:center; font-size:10px; color:#666;'>
            Legacy Document Archive | Converted {date}
        </div>",
    DrawDividerLine = true
});

// Add footer with page numbers
pdf.AddHtmlFooters(new HtmlHeaderFooter
{
    HtmlFragment = @"
        <div style='text-align:center; font-size:10px;'>
            Page {page} of {total-pages}
        </div>"
});

pdf.SaveAs("archived-report.pdf");
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Headers and footers mark documents as archived or add pagination.

How Do I Handle RTF with Embedded Images?

RTF can contain embedded graphics:

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

// RTF with embedded images converts automatically
var pdf = PdfDocument.RenderRtfFileAsPdf("document-with-images.rtf");

// Images are embedded in the PDF
pdf.SaveAs("document-with-images.pdf");
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Embedded images, logos, and charts transfer to the PDF without extra configuration.

How Do I Set Paper Size and Orientation?

Control the output format:

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

// Currently, RenderRtfFileAsPdf uses default settings
// For custom paper sizes, convert RTF to HTML first, then render

var pdf = PdfDocument.RenderRtfFileAsPdf("wide-table.rtf");

// If you need to adjust after conversion, you can transform pages
// Or use the rendering options when available

pdf.SaveAs("wide-table.pdf");
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Standard conversions use letter/A4 sizing. Landscape-heavy content may need post-processing.

How Do I Handle Encoding Issues?

RTF supports multiple character encodings:

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

// IronPDF handles standard RTF encoding automatically
// For files with special characters, ensure the RTF header declares encoding

// Example RTF with Unicode:
string rtfWithUnicode = @"{\rtf1\ansi\ansicpg1252\deff0
{\fonttbl{\f0 Arial;}}
\f0\fs24 Special chars: \u233? (e-acute) \u8364? (euro)
}";

var pdf = PdfDocument.RenderRtfStringAsPdf(rtfWithUnicode);
pdf.SaveAs("unicode-text.pdf");
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Properly formed RTF with encoding declarations converts cleanly.

How Do I Validate RTF Before Converting?

Check files before processing:

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

public PdfDocument SafeConvertRtf(string filePath)
{
    // Basic validation
    if (!File.Exists(filePath))
        throw new FileNotFoundException($"RTF file not found: {filePath}");

    // Check extension
    if (!filePath.EndsWith(".rtf", StringComparison.OrdinalIgnoreCase))
        throw new ArgumentException("File must have .rtf extension");

    // Check RTF signature
    var header = File.ReadAllText(filePath, Encoding.ASCII).Substring(0, 5);
    if (!header.StartsWith("{\\rtf"))
        throw new FormatException("File is not valid RTF format");

    return PdfDocument.RenderRtfFileAsPdf(filePath);
}
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Validate inputs to avoid conversion errors on malformed files.

What About Asynchronous Conversion?

For web applications, don't block threads:

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

public async Task<byte[]> ConvertRtfToPdfAsync(string rtfContent)
{
    return await Task.Run(() =>
    {
        var pdf = PdfDocument.RenderRtfStringAsPdf(rtfContent);
        return pdf.BinaryData;
    });
}
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Wrap synchronous conversion in Task.Run for async contexts.

Quick Reference

Task Method
Convert file PdfDocument.RenderRtfFileAsPdf("file.rtf")
Convert string PdfDocument.RenderRtfStringAsPdf(rtfString)
Add security pdf.SecuritySettings.UserPassword = "pass"
Merge multiple PdfDocument.Merge(pdfList)
Add headers pdf.AddHtmlHeaders(header)

RTF to PDF conversion modernizes legacy documents. One method call transforms outdated formats into universal, secure PDFs.

For additional RTF handling options, see the IronPDF RTF 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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