Utter is a macOS menu bar app for AI-powered voice input and dictation. It supports both fully local on-device inference and remote LLM APIs. Press a hotkey to start recording, release to transcribe, and the result is typed directly into whatever app you're using.
Three output modes are available:
- Verbatim — raw transcription, lowest latency
- Smart Format — transcription cleaned up by an LLM (contextual filler removal, grammar fixes, structured formatting)
- Voice Command — speak a command and get an AI-generated response based on screen context
| Feature | Description |
|---|---|
| Multiple Speech Engines | Apple Speech, WhisperKit, Doubao ASR, or Qwen3-ASR |
| Smart Text Processing | Local MLX Qwen2.5/Qwen3 or remote LLM infers spoken intent — contextual cleanup, "scratch that" restarts, self-correction handling, spoken punctuation, technical terms, numbers/ranges/units, and structured formatting |
| LLM-Owned Spoken Formatting | Spoken casing, no-space dictation, identifiers, file paths, shortcuts, emoji, Markdown tasks, dates/times, quantities, units, formulas, fractions, and digit sequences are handled by the Smart Format / Voice Command prompts instead of local hardcoded rewrite rules |
| Voice Edit Commands | In Voice Command mode, an LLM classifies safe structured actions for replacing, undoing, proofreading, titling, summarizing, drafting replies, making meeting notes, extracting key points/decisions/questions/risks/deadlines/owners/action items, rewriting tone, expanding, making tables/lists, or deleting the previous Utter insertion or selected text |
| Verbatim & Preview Boundary | Verbatim mode, streaming HUD, integration partials, and instant-insert drafts keep ASR text close to raw output with only dictionary, whitespace, duplicate, and non-speech-artifact cleanup |
| Remote LLM Support | OpenAI, Claude (Anthropic format), Gemini, OpenRouter, SiliconFlow, Doubao, Bailian, MiniMax (CN & Global) |
| Global Hotkey | Configurable key (Fn/Ctrl/Shift/Option) with long-press, double-tap, or single-tap activation |
| Translation Dictation | Use a dedicated hotkey chord to speak in one language and insert an English, Chinese, Japanese, Korean, Spanish, French, or German translation |
| Screen Context OCR | Captures on-screen text via ScreenCaptureKit + Vision to help the LLM correct homophones |
| Voice Command Mode | Screen-aware voice assistant — summarize, reply, translate based on what's on screen |
| Input Memory | Recent input history injected as LLM context for better continuity |
| Industry Vocabulary | Choose Medical, Legal, Finance & Accounting, or Software Technology terms for Apple Speech / Whisper biasing and output normalization; personal terms take priority |
| Edit Rules | Personal text replacement rules applied on every output |
| Language Style Presets | Concise / Formal / Casual / Custom prompt per language |
| Input History & Stats | Full history with raw vs. processed comparison, word count stats, configurable retention |
| Bilingual UI | Chinese and English interface, independent of recognition language |
| Sound Feedback | Audio cues on recording start and stop |
| Guided Onboarding | Step-by-step setup: permissions, model download, and first use |
- OS: macOS 26 (Tahoe) or later
- Chip: Apple Silicon (M1 / M2 / M3 / M4)
- Disk: ~400 MB minimum (Apple Speech + Qwen3-0.6B), up to ~4 GB with larger models
Grab the latest .dmg from Releases, open it, and drag Utter.app to Applications.
"Cannot verify the developer" on first launch? The app is not notarized by Apple. Before first run, execute in Terminal:
xattr -cr /Applications/Utter.appOr go to System Settings → Privacy & Security and click "Open Anyway".
# Build .app bundle + .dmg installer
bash scripts/build-app.sh
# Or for development
swift build
swift run OpenType
# Build, sign, and launch the development .app bundle
bash scripts/build-and-run.sh --verify
# Or open in Xcode
open Package.swiftMaterial changes follow the artifact-driven workflow in
docs/sdlc/README.md. Before opening a pull request, run:
bash scripts/sdlc-checks.sh
bash scripts/ci-basic-checks.sh
swift testThe public app is Utter.app. The Swift package product remains OpenType so existing source integrations and upgrade paths continue to work.
- Launch Utter — it appears as a waveform icon in the menu bar
- The onboarding wizard guides you through permissions and model setup
- Grant Microphone and Accessibility permissions (required)
- Wait for the LLM model to download (~335 MB, one-time)
- Hold Fn to start dictating, release to stop and insert text
| Permission | Purpose | Required |
|---|---|---|
| Microphone | Audio capture | Yes |
| Accessibility | Global hotkey + text injection (simulated paste) | Yes |
| Speech Recognition | Apple on-device ASR engine | Only if using Apple Speech |
| Screen Recording | OCR for screen context and Voice Command mode | Optional |
| Network | Model downloads; remote LLM API calls | First run / remote LLM mode |
Utter supports both OpenAI-compatible and Anthropic API formats:
| Provider | API Format | Base URL |
|---|---|---|
| OpenAI | OpenAI | https://api.openai.com/v1 |
| Anthropic Claude | Anthropic | https://api.anthropic.com/v1 |
| Google Gemini | OpenAI | https://generativelanguage.googleapis.com/v1beta/openai |
| OpenRouter | OpenAI | https://openrouter.ai/api/v1 |
| SiliconFlow | OpenAI | https://api.siliconflow.cn/v1 |
| Volcengine Doubao | OpenAI | https://ark.cn-beijing.volces.com/api/v3 |
| Alibaba Bailian | OpenAI | https://dashscope.aliyuncs.com/compatible-mode/v1 |
| MiniMax (China) | OpenAI | https://api.minimax.chat/v1 |
| MiniMax (Global) | OpenAI | https://api.minimaxi.chat/v1 |
| Provider | Local runtime | Default model |
|---|---|---|
| Qwen3-ASR | Native Swift + MLX on Apple Silicon | mlx-community/Qwen3-ASR-1.7B-bf16 |
Qwen3-ASR does not call a hosted ASR API. The app downloads the selected model into the same model storage used by WhisperKit and runs inference locally through native Swift and MLX.
Sources/
├── App/ # Entry point, AppDelegate, AppState, VoicePipeline, AppIcon
├── Audio/ # Microphone capture (AVAudioEngine), sound playback
├── Config/ # AppSettings, ModelCatalog, RemoteModelConfig, Localization
├── Hotkey/ # Global hotkey via CGEvent tap
├── LLM/ # LLMEngine (MLX), RemoteLLMClient (OpenAI/Anthropic)
├── Output/ # Text injection (Accessibility API + clipboard paste)
├── Processing/ # TextProcessor, InputHistory, MemoryStore, personal and industry vocabulary
├── Prompts/ # PromptBuilder, prompt catalogs, style prompt presets
├── Screen/ # Screen OCR (ScreenCaptureKit + Vision)
├── Speech/ # SpeechEngine protocol, WhisperKit, Apple Speech, Doubao ASR, local ASR engines
├── UI/ # SwiftUI: MenuBar, Settings, Onboarding, Overlay, History, Models
└── Resources/ # Localization strings (en/zh-Hans), sounds, app icon
scripts/
├── build-and-run.sh # Build, sign, and launch a development .app bundle
├── build-app.sh # Build release .app bundle and .dmg installer
├── ci-basic-checks.sh # CI guardrails for linked files and resources
├── create-signing-cert.sh # Generate self-signed code signing certificate
├── generate-icon.swift # Generate AppIcon.icns from source PNG
├── test-industry-lexicons.sh # Validate vocabulary recall and non-target preservation
├── unit-test-coverage.sh # Run unit tests with coverage thresholds
└── validate-volc-asr.swift # Validate Volcengine ASR configuration manually
- WhisperKit — offline Whisper speech recognition
- mlx-swift-lm — local LLM inference on Apple Silicon (Qwen2.5 / Qwen3)
- SwiftUI + AppKit — native macOS UI
- ScreenCaptureKit + Vision — screen OCR
- AVAudioEngine — low-latency microphone capture
- Apple Speech Framework — on-device speech recognition
Made with care for Apple Silicon