Setting up tidy in .NET to beautify HTML

Tidy  for those who don't know, was the first beautifier of code, and is the granddaddy of them all. It based of libtidy is a C static and dynamic library that developers can integrate into their applications in order to bring all of Tidy’s power to your favorite tools.

It corrects and cleans up HTML and XML documents by fixing markup errors and upgrading legacy code to modern standards.

However, I don't want to change any HTML itself, I'm just look'm to prettify HTML. 

However for .NET there are not to many good options, surprisingly enough. It's because interpreting HTML is hard, even Microsoft is now using open-source project Chromium as HTML rendering engine https://www.microsoftedgeinsider.com/en-us/download/. 

To integrate into Tidy into your .NET project you can use a managed Tidy .NET wrapper.

Here's how to set-up Tidy to beautify HTML and minimally change HTML input

Here's a quick reference API guide 
http://api.html-tidy.org/tidy/quickref_5.0.0.html#join-classes
There are 93 settings that can affect Tidy's ouput, so it can be exhausting to run through them. Below, has worked for me.

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//After many hours of painstaking analysis, this how to get HTML to be passed correctly byte[] encodedBytesUTF8 = Encoding.UTF8.GetBytes(htmlText); MemoryStream mshtmlText = new MemoryStream(encodedBytesUTF8); try { //THIS DOES NOT WORK, it re-encodes the string improperly, after many hours of painstaking anaylsis //tidydoc = TidyManaged.Document.FromString(cleanHtml); tidydoc = TidyManaged.Document.FromStream(HTMLinput); } catch (Exception tex) { return "tidy HTML parsing error: " + tex.Message; } using ( tidydoc ) { //http://api.html-tidy.org/tidy/quickref_5.0.0.html tidydoc.ShowWarnings = false; tidydoc.Quiet = true; tidydoc.ForceOutput = true; tidydoc.OutputBodyOnly = AutoBool.Auto; tidydoc.DocType = TidyManaged.DocTypeMode.Omit; tidydoc.DropFontTags = false; tidydoc.UseLogicalEmphasis = false; tidydoc.LowerCaseLiterals = false; tidydoc.OutputXhtml = false; tidydoc.OutputXml = false; tidydoc.MakeClean = false; tidydoc.DropEmptyParagraphs = false; tidydoc.CleanWord2000 = false; tidydoc.QuoteAmpersands = false; //This option specifies if Tidy should output unadorned & characters as &. tidydoc.AsciiEntities = false; //Can be used to modify behavior of -c (--clean yes) option. If set to "yes" when using -c, &emdash;, ”, and other named character entities are downgraded to their closest ascii equivalents. tidydoc.PreserveEntities = true; //This option specifies if Tidy should preserve the well-formed entities as found in the input. tidydoc.OutputNumericEntities = true; //This option specifies if Tidy should output entities other than the built-in HTML entities (&, <, > and ") in the numeric rather than the named entity form tidydoc.JoinStyles = false; tidydoc.JoinClasses = false; tidydoc.Markup = true; //prettify open tidydoc.WrapAt = 0; tidydoc.IndentSpaces = 4; tidydoc.IndentBlockElements = TidyManaged.AutoBool.Yes; // this increases file size! (but makes it better to read) tidydoc.InputCharacterEncoding = TidyManaged.EncodingType.Utf8; tidydoc.CharacterEncoding = TidyManaged.EncodingType.Utf8; //For raw, Tidy will output values above 127 without translating them into entities. tidydoc.OutputCharacterEncoding = TidyManaged.EncodingType.Utf8; tidydoc.JoinStyles = false; tidydoc.MergeDivs = AutoBool.No; tidydoc.MergeSpans = AutoBool.No; tidydoc.OutputHtml = true; tidydoc.UseXmlParser = false; tidydoc.AddTidyMetaElement = false; try { tidydoc.CleanAndRepair(); //required } catch (Exception car) { return "tidy HTML clean && repair error: " + car.Message; } try { cleanHtml = tidydoc.Save(); } catch (Exception save) { return "tidy HTML save error: " + save.Message; } }