A lightweight and performant C# library designed for rapidly converting Rich Text Format (RTF) files into plain text.
- Fast: Up to 400x faster than RichTextBox — and over 100x faster at minimum
- Accurate: All characters converted correctly — even Wingdings
- Fully cross-platform
- Can read from forward-only streams such as DeflateStream
- We even support this obscure nonsense
Install the library via NuGet:
dotnet add package ReasonableRTF.Standard
Use the static ConvertRtf.ToText() method to do a one-off conversion:
using ReasonableRTF;
using ReasonableRTF.Enums;
using ReasonableRTF.Models;
// ...
RtfResult result = ConvertRtf.ToText(@"C:\rtf_files\some_file.rtf");
if (result.Error == RtfError.OK)
{
// Conversion was successful
string plainText = result.Text;
Console.WriteLine("Converted Text:\n" + plainText);
}
else
{
// Handle conversion errors
Console.WriteLine($"Conversion Error: {result.Error} at byte position: {result.BytePositionOfError}");
if (result.Exception != null)
{
Console.WriteLine($"Exception Details: {result.Exception.Message}");
}
}You can create and reuse an RtfToTextConverter instance to minimize overhead when converting many files:
using ReasonableRTF;
using ReasonableRTF.Enums;
using ReasonableRTF.Models;
// ...
RtfToTextConverter converter = new RtfToTextConverter();
foreach (string fileName in Directory.EnumerateFiles(@"C:\rtf_files\", "*.rtf"))
{
RtfResult result = converter.Convert(fileName);
if (result.Error == RtfError.OK)
{
// Conversion was successful
string plainText = result.Text;
Console.WriteLine("Converted Text:\n" + plainText);
}
else
{
// Handle conversion errors
Console.WriteLine($"Conversion Error: {result.Error} at byte position: {result.BytePositionOfError}");
if (result.Exception != null)
{
Console.WriteLine($"Exception Details: {result.Exception.Message}");
}
}
}For efficiency, an RtfToTextConverter will not trim its internal growable buffers between conversions. You can use the ResetMemory() method to reset these buffers back to their default sizes. This way, you can keep one RtfToTextConverter instance around indefinitely without worrying about memory use.
The RtfResult struct provides full details about the conversion process, ensuring you can robustly handle success and failure cases.
| Property | Type | Description |
|---|---|---|
Text |
string |
The converted plain text. |
Error |
RtfError |
The error code. This will be RtfError.OK upon successful conversion. |
BytePositionOfError |
int |
The approximate position in the data stream where the error occurred, or -1 if no error. |
Exception |
Exception? |
The caught exception, or null if no exception occurred during conversion. |
For more control over the output, you can provide an instance of the RtfToTextConverterOptions class.
RtfToTextConverterOptions options = new RtfToTextConverterOptions
{
ConvertHiddenText = true, // Include text marked as hidden
LineBreakStyle = LineBreakStyle.LF // Use Unix-style line breaks
};
RtfResult result = ConvertRtf.ToText(@"C:\rtf_files\some_file.rtf", options);
// ... check resultThe available options are documented in RtfToTextConverterOptions.cs.
BenchmarkDotNet v0.15.8, Windows 11 (10.0.26200.8655/25H2/2025Update/HudsonValley2)
AMD Ryzen 5 5600 3.50GHz, 1 CPU, 12 logical and 6 physical cores
.NET SDK 10.0.301
[Host] : .NET 10.0.9 (10.0.9, 10.0.926.27113), X64 RyuJIT x86-64-v3
DefaultJob : .NET 10.0.9 (10.0.9, 10.0.926.27113), X64 RyuJIT x86-64-v3
| Method | Mean | Error | StdDev | Speed | |
|---|---|---|---|---|---|
| RichTextBox_FullSet | 3,331.340 ms | 6.2250 ms | 5.5183 ms | 43.59 MB/s | 1x |
| RichTextBox_NoImageSet | 1,432.217 ms | 3.7089 ms | 3.4693 ms | 2.47 MB/s | 1x |
| ReasonableRTF_FullSet | 15.051 ms | 0.0343 ms | 0.0320 ms | 9647.98 MB/s | 221x |
| ReasonableRTF_NoImageSet | 3.372 ms | 0.0055 ms | 0.0046 ms | 1050.91 MB/s | 425x |
| ReasonableRTF_FullSet_Streamed | 16.851 ms | 0.0570 ms | 0.0533 ms | 8617.40 MB/s | 198x |
| ReasonableRTF_NoImageSet_Streamed | 3.465 ms | 0.0080 ms | 0.0075 ms | 1022.70 MB/s | 413x |
BenchmarkDotNet v0.15.8, Windows 11 (10.0.26200.8655/25H2/2025Update/HudsonValley2)
AMD Ryzen 5 5600 3.50GHz, 1 CPU, 12 logical and 6 physical cores
[Host] : .NET Framework 4.8.1 (4.8.9337.0), X64 RyuJIT VectorSize=256
DefaultJob : .NET Framework 4.8.1 (4.8.9337.0), X64 RyuJIT VectorSize=256
| Method | Mean | Error | StdDev | Speed | |
|---|---|---|---|---|---|
| RichTextBox_FullSet | 2,779.775 ms | 3.9318 ms | 3.2833 ms | 52.24 MB/s | 1x |
| RichTextBox_NoImageSet | 992.237 ms | 2.5478 ms | 2.2585 ms | 3.57 MB/s | 1x |
| ReasonableRTF_FullSet | 18.969 ms | 0.0621 ms | 0.0581 ms | 7655.21 MB/s | 147x |
| ReasonableRTF_NoImageSet | 4.686 ms | 0.0122 ms | 0.0108 ms | 756.22 MB/s | 212x |
| ReasonableRTF_FullSet_Streamed | 21.456 ms | 0.0797 ms | 0.0746 ms | 6767.89 MB/s | 130x |
| ReasonableRTF_NoImageSet_Streamed | 4.766 ms | 0.0116 ms | 0.0108 ms | 743.53 MB/s | 208x |
BenchmarkDotNet v0.15.8, Windows 11 (10.0.26200.8655/25H2/2025Update/HudsonValley2)
AMD Ryzen 5 5600 3.50GHz, 1 CPU, 12 logical and 6 physical cores
[Host] : .NET Framework 4.8.1 (4.8.9337.0), X86 LegacyJIT
DefaultJob : .NET Framework 4.8.1 (4.8.9337.0), X86 LegacyJIT
| Method | Mean | Error | StdDev | Speed | |
|---|---|---|---|---|---|
| RichTextBox_FullSet | 6,932.056 ms | 131.6848 ms | 140.9013 ms | 20.95 MB/s | 1x |
| RichTextBox_NoImageSet | 2,885.139 ms | 57.0121 ms | 81.7651 ms | 1.23 MB/s | 1x |
| ReasonableRTF_FullSet | 41.745 ms | 0.1710 ms | 0.1599 ms | 3478.54 MB/s | 166x |
| ReasonableRTF_NoImageSet | 8.240 ms | 0.0178 ms | 0.0158 ms | 430.06 MB/s | 350x |
| ReasonableRTF_FullSet_Streamed | 45.633 ms | 0.0670 ms | 0.0594 ms | 3182.17 MB/s | 152x |
| ReasonableRTF_NoImageSet_Streamed | 8.057 ms | 0.0220 ms | 0.0205 ms | 439.82 MB/s | 358x |
- All basic plain text, hex-encoded chars, Unicode-encoded chars
- Symbol fonts (Wingdings 1, 2 and 3, Webdings, Symbol, and Zapf Dingbats) converted to Unicode equivalents
- Characters specified as "SYMBOL" field instructions
- Undocumented use of the \langN keyword to specify character encoding - old versions of RichTextBox used to support this
- Tables: Cells and rows have spaces between them, but not much functionality beyond that.
- Lists: Numbers and bullets show up (that's better than RichTextBox most of the time), but indentation usually doesn't.
- Footnotes
- "HYPERLINK" field instruction value
- Math objects
The original code for this RTF converter was written by Brian Tobin and is licensed under the MIT License (Copyright 2024-2026 Brian Tobin). For the full license text, please refer to the LICENSE file ReasonableRTF.
Flamifly contributed to the readme (installation, quick start, documentation, etc), and ported the original .NET-only version to .NET Standard.