In TextEdit, compose page in Rich Text mode.
Save As>xxxx. At bottom of Save dialog box is a File Format pulldown menu.
Select HTML from the list of 4 choices. The .html extension will appear in the title box.
Leave the “hide extension” box UNchecked.
Save to preferred destination.
Doc should appear with Safari or your default browser’s icon and open as a web page.
Selecting “view source” with browser will reveal headers, footers and tags as placed by
TextEdit.
Works adequately, with type size, color, bolds and italics rendering as composed.
or, if you know basic HTML,
Open a new document, under top menubar “Format”select “make plain text” if TextEdit it is currently in RTF mode.
Compose document in plain text, manually entering all appropriate HTML tags.
When saving text document, you’ll have to manually append .html extension and override the app’s insistence on wanting to use “.txt”.
Open and view as above.