Markdown WYSIWYG editor with live preview
TOAST UI Editor is a full-featured Markdown and WYSIWYG editor by NHN that supports GFM standard syntax with extensible chart and UML rendering. It offers dual editing modes with seamless switching, live preview with scroll sync, syntax highlighting, and a plugin architecture for adding color pickers, table merging, code highlighting, and diagram support. The editor ships with React, Vue, and vanilla JavaScript wrappers and supports 20+ languages.