Sumi

System-wide speech-to-text for macOS. Free and open source.

Press a hotkey anywhere. Speak. The text pastes at your cursor — rewritten by an AI that knows which app you're in.

English | 繁體中文 | 简体中文

Gmail — formats as a proper email	Notion — clean structured prose	Telegram — casual, conversational

brew tap alan890104/sumi && brew install --cask sumi

Download DMG · Releases · Issues

---

Why Sumi?

🎯 Per-App AI Polish Every app gets a different LLM prompt. Slack sounds like Slack. Gmail sounds like email. Terminal gets clean commands. 18 built-in rules — write your own, or describe what you want and the AI generates the rule.	🔒 Fully Local Run everything on-device: Whisper or Qwen3-ASR for speech recognition, local LLM for rewriting. Audio never leaves your Mac. You can verify it — the code is here.
🗣 Speaker Diarization Meeting mode transcribes continuously in the background. Transcripts are labelled by speaker with timestamps. Import existing audio files for retroactive transcription.	✏️ Edit by Voice Select any text, press Option+E, say what you want done. "Make this more formal." "Translate to Japanese." "Shorten it." The AI rewrites and pastes back.
☁️ Cloud or Local — Your Choice BYOK for everything: Groq, OpenAI, Deepgram, Azure, Gemini, OpenRouter, or any OpenAI-compatible endpoint. No Sumi account. No subscription.	🌏 58 UI Languages The interface ships in 58 locales. Traditional Chinese users get automatic zh-CN → zh-TW normalization on transcription output.

---

Same sentence, three apps

You say: "um I think the project is kind of behind schedule and we should probably have a meeting to figure out what to do next"

LINE (casual)	I think the project is behind schedule, we should have a meeting to figure out what to do next
Slack (professional)	I think the project is behind schedule. We should have a meeting to discuss next steps.
Gmail (email)	Hi, I believe the project is currently behind schedule. Could we schedule a meeting to discuss the next steps? Best regards

---

How it works

1. App lives in the menu bar — nothing else on screen.
2. Click into any text field, anywhere on your Mac.
3. Press Option+V. A floating capsule appears with the waveform.
4. Speak.
5. Press Option+V again. Text pastes.

Edit by Voice: select text → Option+E → say what to do with it. Meeting Mode: press Option+M to toggle continuous background transcription into a note file.

---

What it runs on

Speech recognition — Local: Whisper (Metal GPU, 7 model sizes from 148 MB to 1.6 GB) or Qwen3-ASR. Cloud: Groq, OpenAI, Deepgram, Azure, any custom endpoint.

LLM rewriting — Local: Qwen3-8B, Qwen2.5-7B, Llama 3 Taiwan 8B via candle (Metal/CUDA). Cloud: OpenAI, Groq, Gemini, GitHub Models, OpenRouter, SambaNova, any OpenAI-compatible endpoint.

Resource usage — Idle: ~130 MB, 0% CPU. Local transcription: ~730 MB RSS, <20% CPU (Metal). Cloud mode: ~7 MB during recording, back to 0% when done.

Other details — Silero VAD for silence filtering · custom pronunciation dictionary · transcription history with audio export · customizable hotkeys

---

Comparison

Note

This reflects our best understanding at the time of writing. Competitors update frequently — corrections welcome via issues or PRs.

	Sumi	Built-in Dictation	Typeless	Wispr Flow	VoiceInk	SuperWhisper
Price	Free	Free	4K words/wk free, $12-30/mo	2K words/wk free, $12-15/mo	$25-49 (one-time)	Free trial, ~$8/mo
Open Source	✅ GPLv3	❌	❌	❌	✅ GPLv3	❌
Local STT	✅	✅ Apple Silicon	❌ Cloud only	❌ Cloud only	✅	✅
Cloud STT	✅ BYOK	❌	✅	✅	✅ Optional	✅
AI Polish	✅	❌	✅	✅	✅	✅
Local LLM Polish	✅ 3 models	❌	❌	❌	❌	✅
Per-App Rules	✅ 18 presets + custom	❌	❌	✅ Styles	✅ Power Modes	✅ Custom modes
Context-Aware	✅ App + URL	❌	✅ App	✅ App	✅ App	✅ Super Mode
Edit by Voice	✅	❌	✅	✅	❌	❌
Dictionary	✅	❌	✅	✅	✅	✅
History	✅ + audio export	❌	✅	✅	✅	✅
Meeting notes	✅ + speaker labels	❌	—	❌	—	✅
Platforms	macOS	macOS, iOS	macOS, Win, iOS, Android	macOS, Win, iOS, Android	macOS	macOS, Win, iOS

---

Installation

Homebrew (recommended)

brew tap alan890104/sumi
brew install --cask sumi

Download DMG

1. Download the latest DMG from GitHub Releases.
2. Open the DMG, drag Sumi into /Applications.
3. The app isn't notarized yet, so macOS will block it. Run this first:

   xattr -cr /Applications/Sumi.app

4. On first launch: grant Microphone access and enable Accessibility under System Settings → Privacy & Security → Accessibility (required for auto-paste).

Build from source

Requires Rust and cargo install tauri-cli --version "^2".

git clone https://github.com/alan890104/sumi.git
cd sumi
cargo tauri dev      # dev mode
cargo tauri build    # production .dmg

Windows (CUDA)

Metal is macOS-only. On Windows:

# CPU only
cargo tauri dev --no-default-features

# NVIDIA CUDA (requires CUDA Toolkit, LLVM, Ninja, CMake)
bash dev-cuda.sh
bash dev-cuda.sh --release

---

License

GPLv3