Skip to main content

Voice to text for Mac

Mumbli turns your Mac into a voice-first machine. Hold Fn, speak naturally, and polished text appears right where your cursor is — in any application. No dictation box. No copy-paste. No app-specific plugins. Just speak and type.

Why Mumbli

Apple Dictation is built into macOS, but it has limits: no polishing, no custom vocabulary, no way to handle filler words or self-corrections. It works fine for short phrases but falls apart for longer dictation. Mumbli fills the gap:
  • Filler word removal — “um”, “uh”, and verbal tics are cleaned out automatically
  • Self-correction handling — Say “at 4 pm, actually 3 pm” and get “at 3 pm”
  • Grammar and punctuation — Light cleanup without rewriting your voice
  • Custom vocabulary — Add names, jargon, and technical terms that speech engines get wrong
  • Multi-language — Language detection is automatic, no switching needed

How it works

1

Hold Fn to record

Press and hold the Fn key. A small overlay appears near your cursor showing that Mumbli is listening. Or double-tap Fn for hands-free mode.
2

Speak naturally

Talk at your normal pace. Audio is captured at 16 kHz mono and sent to an AI transcription service.
3

Get polished text

The raw transcription passes through a lightweight LLM that cleans it up while preserving your voice. Text is injected at the cursor via the Accessibility API.

Speed matters

Mumbli offers two engine configurations:
EngineTranscriptionPolishEnd-to-end
StandardElevenLabs ScribeGPT-5.4 Nano~3-5 seconds
FastGroq WhisperGroq Llama 3.1 8B~0.5-1 second
The Fast engine delivers sub-second transcription — faster than you can move your hands back to the keyboard.

Custom vocabulary

Speech engines struggle with proper nouns, brand names, and technical terms. Mumbli lets you add a custom vocabulary list in Settings. These words are:
  1. Sent as hints to the transcription engine, biasing it toward correct spellings
  2. Injected into the polishing prompt so the LLM fixes any remaining errors
Real-world benchmark: accuracy jumped from 36% to 100% across 11 vocabulary instances.

Works everywhere

Mumbli uses the macOS Accessibility API to inject text at your cursor. This means it works in:
  • Browsers (Chrome, Safari, Firefox, Arc)
  • Email clients (Mail, Outlook, Gmail)
  • Messaging apps (Slack, Discord, Messages, Telegram)
  • IDEs (VS Code, Xcode, IntelliJ)
  • Note-taking apps (Notes, Obsidian, Notion)
  • Terminals and command lines
  • Any app with a text field
No integrations to configure. No plugins to install.

Permissions

Mumbli needs three macOS permissions to work:
PermissionWhy
MicrophoneAudio capture for dictation
AccessibilityInjecting text at the cursor
Input MonitoringDetecting Fn key presses
You’ll be prompted on first launch. All processing uses your own API keys — nothing is stored on external servers.

Download Mumbli

Free and open source. macOS 13.0+ required.