pure-text editor on Mac that works exactly like old Windows Notepad

You want a simple, pure-text editor on Mac that works exactly like old Windows Notepad — meaning:

Great news — you have multiple perfect solutions on macOS.

✅ The Best “Old Notepad-Style” Options for Mac

macOS TextEdit supports rich text by default, but you can force it to always open in pure plain text mode.

Open TextEdit
Go to TextEdit > Settings
Select New Document
Under Format, choose Plain Text
Go to the Open and Save tab
Turn ON:
- ✓ Ignore rich text commands in HTML files
- ✓ Display HTML files as HTML code instead of formatted text

✔ No bold
✔ No colors
✔ No font sizes
✔ No rich-text paste
✔ No styling ever

If you want something even cleaner:

Why it's perfect:

Why people love it:

macOS has a built-in shortcut:

This pastes WITHOUT formatting in many apps (Chrome, Safari, Notes, Slack, etc.)

If you want global control:

Now Command+V will ALWAYS paste plain text everywhere.

If you want a browser tool:

Paste → formatting removed.

Based on your message:

“I want 1 editor like old Notepad where I paste anything and it removes all formatting automatically.”

I recommend:

Both behave exactly like old Windows Notepad.