Local · open-source voice-to-text

Speak anywhere.
It writes for you.

Hold a key and talk into any app. Murmur turns rambling speech into clean, formatted text — transcribed locally with Whisper, polished by AI, and dropped right at your cursor.

Free & open source · macOS 12+ · Apple Silicon & Intel · clears Gatekeeper for you
Privacy by architecture

Your voice never leaves your laptop.

Most dictation tools stream your microphone to someone else's servers. Murmur doesn't. Transcription and the AI cleanup pass both run locally — so the most personal data you produce all day stays on the one machine you control.

Your device
You speak
hold ⌥ Space
Whisper transcribes
openai/whisper · local
AI polishes
filler & grammar
Text inserted
at your cursor
the cloud — never touched
Processed on-device

Whisper runs on your CPU or GPU. Audio is transcribed in memory and discarded — never written to disk, never sent anywhere.

No account, no cloud

No sign-up, no sync, no telemetry, no background phone-home. Download it, grant mic access, and start talking.

Open source, forever

Every line is auditable on GitHub. MIT-licensed and free — no trial, no seat count, no paywall waiting at the end.

Whisper, your way

From instant
to flawless.

Murmur ships every OpenAI Whisper size. Pick the one that fits your machine — smaller is faster, larger is sharper. They all run entirely on-device.

ModelDownloadSpeedAccuracyBest for
tiny 75 MB 32× realtime Quick notes
base 142 MB 16× realtime Everyday chat
small 466 MB 6× realtime Balanced
medium 1.5 GB 2× realtime High accuracy
large-v3 2.9 GB 1× realtime Best qualityDefault
Audio never leaves your device. Runs on CPU or GPU · switch models any time
The desktop app

A quiet home for everything you've said.

Beyond the floating overlay, Murmur is a full desktop app — history, stats and every setting — native on macOS, Windows and Linux.

Good morning, Alex.
You've dictated 12 times today.
Words today
1,248
Avg WPM
142
Day streak
7days
Recent dictations
Let's move the launch to Friday and send the recap notes tonight.
2m ago · 12 words
Can you review the pull request before standup? I left two comments.
18m ago · 13 words
Remember to book the venue and confirm catering by end of week.
1h ago · 12 words
Draft a reply to the design team about the new onboarding flow.
3h ago · 12 words
Home
Every dictation, searchable — with words saved and your streak.
Voice & model
All processing happens on this device.
Microphone
Input device for dictation
MacBook Pro Mic
Hotkey
Hold to talk
⌥ Space
Language
Auto-detect on by default
English
Transcription model
tiny75 MB · 32×
small466 MB · 6×
medium1.5 GB · 2×
large-v32.9 GB · best quality
Voice & model
Mic, hotkey, language and the Whisper picker, all on-device.

Stop typing.
Start talking.

Murmur installs in under a minute and works in every app you already use. No account, no cloud, no catch — just hold the key and speak.

Free & open source · macOS 12+ · Apple Silicon & Intel · clears Gatekeeper for you