On-device ASR on Mac — how local speech recognition works
Updated June 2026 · macOS 13+
On-device ASR (automatic speech recognition) means the model that turns your speech into text runs on your Mac instead of a remote server. Your audio is processed locally, never uploaded, and it works offline. This page explains what that means, why it matters, how accurate it is, and which Mac apps do it — including Vlow, which uses the open-source FireRedASR model on-device.
What is on-device (local) ASR?
ASR is the technology that converts spoken audio into written text. With cloud ASR, your microphone audio is streamed to a company's servers, transcribed there, and sent back. With on-device ASR, a speech model is downloaded onto your Mac and does the work locally — so there's nothing to upload and nothing to wait on a network for.
Why run speech recognition locally?
- Privacy — your voice never leaves your machine; nothing is stored on someone else's servers.
- Offline — it works on flights, on closed corporate networks, and anywhere without internet.
- Reliability & latency — no round-trip to a server, no outages from a remote service.
- Compliance — keeping audio on-device avoids much of the data-transfer surface that privacy rules focus on.
Is on-device ASR accurate enough?
A few years ago, the best speech models only ran in the cloud. That's no longer true: open models now run efficiently on Apple Silicon and Intel Macs and are accurate for everyday dictation. Vlow uses FireRedASR (Apache-2.0), an open, commercially-usable model, on-device — and because the model is swappable, recognition keeps improving as newer models ship.
Mac apps that run ASR locally
| App | On-device | Best for |
|---|---|---|
| Vlow | ✓ (FireRedASR) | Live dictation + structured output + weekly reports |
| Superwhisper | ✓ | System-wide dictation with modes |
| MacWhisper | ✓ | File & meeting transcription |
| VoiceInk | ✓ | Open-source dictation |
| macOS built-in dictation | ✓ (offline option) | Basic free dictation |
Information as of June 2026; features and availability may change.
How Vlow uses on-device ASR
Vlow loads FireRedASR onto your Mac and runs it locally for live dictation: press a hotkey, speak, and clean text appears at your cursor in any app. It then goes a step further than a raw transcript — shaping speech into structured output (prompt / commit / task / doc) and auto-compiling weekly reports — all while your audio stays on the device.
FAQ
What is on-device ASR?
The speech-to-text model runs on your Mac, not a server. Audio is processed locally, never uploaded, and works offline.
Is it accurate?
Yes — modern on-device models (Vlow uses FireRedASR) are accurate for everyday dictation and improve each release.
Which Mac apps run ASR locally?
Vlow, Superwhisper, MacWhisper, VoiceInk, and the offline mode of macOS built-in dictation.
Does on-device ASR work offline?
Yes — that's a core benefit; no internet is required.