Here Mudassar Ahmed Khan has explained with an example, how to use Rich Text Editor (WYSIWYG Editor) in ASP.Net MVC 5 Razor.
Rich Text Editor (WYSIWYG Editor) in ASP.Net MVC 5 Razor will be implemented using TinyMCE RichTextBox (RichTextEditor) which is a JavaScript plugin and is applied to the HTML TextArea element.
This article will also illustrate how to validate contents of Rich Text Editor (WYSIWYG Editor) using Data Annotations in ASP.Net MVC 5 Razor.