Online rich-text html-editors
Wikipedia: Many WYSIWYG Editors
Online HTML Editor (Free): HTML.am aims primarily at beginners.
https://www.html.am/html-editors/online-html-editor.cfm
HTML.am
TinyMCE : one of the more popular open source web-based WYSIWYG editor.
TinyMCE
https://www.tiny.cloud/docs/demo/full-featured/
or
Simple HTML Editor using tinyMCE
http://htmleditor.in/index.html