On-device stays on-device
In on-device mode, everything happens on your Mac. Audio is captured, transcribed, and cleaned up locally; none of it is sent anywhere. Your models, settings, dictionaries, and history are stored in your user Library on your own machine.
What the cloud engine sends
When you use the Cloud (Pro) engine — the default whenever your plan or trial includes it — your audio streams through the Murmurtale backend for AI speech recognition in our cloud. A second cloud transcription of each finished dictation is coming in 1.1.6. Light AI formatting for punctuation and dialogue applies in Fiction mode only; Plain mode and on-device mode get no AI formatting. It never rewrites your prose. The result is then returned. That is the trade for cloud quality. The on-device tier remains available anytime you want nothing to leave your Mac.
Telemetry
Murmurtale can send crash and error telemetry to help fix problems. You can turn it off in Preferences.