Apple Dictation on Mac
Dictation built into macOS that types speech anywhere you can type, processed on the Mac or on Apple servers depending on what Keyboard settings show.
Dictation built into macOS
“When you use Dictation, your device will indicate in Keyboard Settings if your audio and transcripts are processed on your device and not sent to Apple servers.”
apple.com
“Otherwise, the things you dictate are sent to and processed on the server, but will not be stored unless you opt in to Improve Siri and Dictation.”
apple.com