textEdit issue still today

You can't create html files by changing the extension. If you start with a rich text document, all you need to do is hold down the option key and choose "Save as" and change the format to HTML. That doesn't work with text, but text is its own specific format. TextEdit is not a good choice for creating HTML, regardless.

When you have plain text or have even opened a Word docx or Open Document Text (odt) document in TextEdit, one simply needs to press the option key with File menu : Save As… panel, select Web Page (html) and give the Save as document a name: foo.html and click save. Then open that file in your choice of browser.

It is better to use a real text editor among those already mentioned, but otherwise, time to brush up on TextEdit:

TextEdit User Guide for Mac - Apple Support

BBedit, MacVim, lots of fine GUI plain-text text editors around.

Other options here including purpose-built HTML editors such as SeaMonkey Composer, and Adobe Dreamweaver and its alternatives, too.

If you want to automate this rename (as a droplet or otherwise), I’d expect some variation of a Shortcut or AppleScript or shell script can do the rename, too.

Have you reported it to Apple?

Though I doubt that TextEdit gets much developer love.

Product Feedback - Apple

VikingOSX wrote:

When you have plain text

Doesn't work for plain text. The only options for plain text are encoding.