RTF to HTML .Net is 100% C# assembly to convert RTF, Text and DOCX documents to HTML 3.2, HTML 4.01, HTML5 with CSS and XHTML 1.01. Absolutely standalone solution, doesn't require MS Office or any other. Requires only .NET Framework 4.6.2 and up or .NET 6.0 and up.
$ dotnet add package SautinSoft.RtfToHtml

SautinSoft.RtfToHtml is .NET assembly to convert Text, RTF, DOCX to HTML. Provides your by API to transform Word documents to HTML5, 4.01, 3.2, XHTML with a lot of converting options.
Are you ready to give RTF to HTML .NET a try? Simply execute Install-Package sautinsoft.rtftohtml from Package Manager Console in Visual Studio to fetch the NuGet package. If you already have RTF to HTML .NET and want to upgrade the version, please execute Update-Package sautinsoft.rtftohtml to get the latest version.
string inpFile = @"..\..\..\..\example.rtf";
string outfile = Path.GetFullPath("Result.html");
RtfToHtml r = new RtfToHtml();
r.Convert(inpFile, outfile, new HtmlFixedSaveOptions() {Title = "SautinSoft Example." });
string inpFile = @"..\..\..\..\example.docx";
string outfile = Path.GetFullPath("Result.html");
RtfToHtml r = new RtfToHtml();
r.Convert(inpFile, outfile, new HtmlFixedSaveOptions() {Title = "SautinSoft Example." });
string inpFile = @"..\..\..\..\example.txt";
string outfile = Path.GetFullPath("Result.html");
RtfToHtml r = new RtfToHtml();
r.Convert(inpFile, outfile, new HtmlFixedSaveOptions() {Title = "SautinSoft Example." });