Speak naturally.Keep it private.
Turn your voice into polished text in any app — processed locally on your PC or Mac through key guarantees like No uploaded audio, 0 cloud transcripts, and Zero data selling
“hey team quick update on the latency benchmarks real time factor dropped to zero point two please test and report any bugs in eng channel”
Works instantly anywhere you can place a cursor
No browser plugins, no custom integrations, and zero clipboard overwrites. Murmur simulates native OS keyboard events directly into the frontmost window.
Yourvoiceisyourfastesttool.Turnunfilteredthoughtsintopristinewriting,code,anddecisionswithouttouchingthecloud.
Whisper AI inference runs directly on your Apple Silicon Neural Engine or Windows DirectML GPU with zero cloud subscriptions, zero telemetry, and complete offline privacy.
100% On-Device Compute
All acoustic feature extraction and token decoding run directly in local GPU/Neural Engine memory. No cloud roundtrips, no API keys, and no rate limits.
Zero Telemetry or Audio Logs
Your microphone audio never touches a remote server. Verified by packet inspection tools like Wireshark and LuLu. 0 bytes outbound network egress.
Universal OS Injection
Dictate into Cursor, Slack, Notion, Xcode, or Terminal at the OS level. Murmur simulates native key events directly without overwriting your clipboard history.
Test Murmur in your browser.
Experience how Murmur turns unstructured messy speech into formatted writing while stripping filler words with zero cloud latency.
Backend Refactor Note
Coding & Architecture“we need to refactor the payment gateway to use exponential backoff with jitter and add an idempotent key to prevent double charging on stripe webhooks”
Beat the cloud on latency.
Local AI is only compelling if it feels instantaneous. We engineered Murmur in native Rust to outpace cloud WebSocket pipelines at every stage.
Tail Latency (Speech End → Injected)
Cloud dictation pays a mandatory network round-trip penalty (DNS + TLS handshake + WebSocket upload + cloud inference queue). Murmur decodes inside GPU VRAM immediately.
Make Murmur sound like you.
Murmur adapts to how you write in different apps. Set a different style for messages, work chats, emails, and code editors—computed 100% locally on your machine.
“hey are you free for lunch tomorrow let's do 12 if that works for you”
Hey, are you free for lunch tomorrow? Let’s do 12 if that works for you.
One voice input. Formatted for every app.
Murmur senses the frontmost active window and shapes tone, punctuation, and layout to fit the medium.
“hey mark we just merged the auth token rotation fix to main let me know if staging looks good thanks”
Own your customization.
Generic cloud dictation gives you one rigid output style. Murmur gives you complete local automation, vocal snippets, and portable dictionaries.
Voice-Triggered Text Snippets & Macros
Define vocal expanders. When you say 'bug template', 'schedule link', or 'invoice address', Murmur replaces the phrase with your structured schema immediately.
“insert bug template”
### [Bug]: Title - **Steps to Reproduce:** 1. Open dashboard settings 2. Toggle Air-Gap mode - **Expected:** Sockets close immediately - **Actual:** Verified 0 bytes egress - **Environment:** Murmur v0.1.0 · macOS Sonoma
Features that solve real daily jobs.
Built for developers, lawyers, healthcare professionals, and founders who cannot—and will not—stream sensitive voice data to the cloud.
“Speak the messy first draft. Paste the polished version.”
Speak freely with false starts and filler words. Murmur strips ums, ahs, and repetitions, injects proper punctuation, and outputs clean paragraphs ready to send.
“One shortcut works wherever you write.”
Press Option+Space (macOS) or Alt+Space (Windows) in any text field. Speak naturally and text pastes directly at your cursor via native OS input injection.
“Your client notes and private thoughts stay yours.”
Inference runs 100% on your local CPU/GPU using whisper.cpp. Audio is held only in RAM and deleted on decode. Zero cloud telemetry, zero remote databases.
“Dictate on a plane, in a hotel, or anywhere Wi-Fi fails.”
Whisper weights execute completely offline on your device. Transcribe on 35,000-ft flights, in subways, or in secure air-gapped rooms with zero internet connection.
“Teach it client names, code terms, medications, or product names.”
Add proprietary names, code symbols, technical acronyms, or medication terms. Murmur biases recognition weights to achieve flawless accuracy.
“Private dictation in the languages you actually use.”
Automatic language detection across 99 languages. Dictate in Spanish, German, Japanese, French, or English without cloud transmission or reconfiguring settings.
How Murmur works in three steps.
No window switching or manual copying. Speak and your thoughts become structured writing.
Press your global shortcut
Tap Option+Space on macOS or Alt+Space on Windows from any focused application to trigger the minimal pill.
Speak at your natural pace
Speak naturally in your preferred tone. Local Whisper models decode audio streaming chunks concurrently on your GPU.
Receive formatted text instantly
Release the shortcut. Murmur clears filler sounds, structures sentences, and pastes text directly into your document.
Cloud dictation vs. Local dictation.
Cloud tools protect data with privacy policies. Murmur protects data by keeping your dictation on your device in the first place.
The Local-First Difference: You don't have to trade speed, usability, or smart formatting to get complete air-gapped privacy.
| Capability | MurmurLocal-First (Free MIT) | Wispr Flow | Superwhisper |
|---|---|---|---|
| Architecture & Data Boundary | 100% On-Device (Zero cloud upload) | Cloud transcription (Audio uploaded) | Hybrid (Cloud for advanced) |
| Privacy Guarantee Mechanism | Physical architecture (Zero bytes sent) | Policy & settings based | Policy based |
| Offline Dictation (Planes & Travel) | |||
| Universal Global Hotkey (Any App) | |||
| Filler Word Stripping & Punctuation | Instant local formatting | Cloud LLM | Local / Cloud |
| Custom Jargon & Phonetic Biasing | Unlimited on-device dictionary | Cloud managed | Pro tier only |
| macOS & Windows Parity | Native macOS & Windows (Metal / DirectML) | macOS & Windows preview | macOS only |
| Latency | Under 180 ms (Local GPU) | 300 to 700 ms (Network ping) | 250 ms |
| Pricing & License | Free & Open Source (MIT) | $144 / year subscription | $200 lifetime |
Calculate your speaking speed dividend.
Human speech flows at ~160 words per minute while average typing tops out at ~40 words per minute.
Select the right model for your device.
Murmur runs 100% on device with Whisper GGML models. Whisper Small (190 MB) is included free by default; download any model weights with one click.
Whisper Small (q5_1)
Default RecommendedThe official default for all users. Optimal balance of sub-200ms speed, low memory footprint, and accurate punctuation.
Trusted by engineers, clinicians, and writers.
Practical feedback from professionals who rely on on-device speech recognition daily.
“Murmur completely replaced cloud dictation tools for my daily engineering work. I write code comments, PR reviews, and Slack messages with my voice. Being 100% offline and free is an incredible achievement.”
Elena Rostova
Staff Software Engineer
“As a physician, HIPAA compliance is strictly non-negotiable. I cannot use cloud speech tools. Murmur runs locally on my laptop with zero network traffic and recognizes medical terminology reliably.”
Dr. Julian Vance
Clinical Neurologist
“I dictated over 40,000 words of my latest manuscript with Murmur. The filler word removal cleans false starts without interrupting my natural drafting rhythm.”
Marcus Sterling
Author & Essayist
“Alt+Space on Windows with DirectML is instantaneous. The real time factor is under 0.20x. My wrist typing strain has completely disappeared.”
Siddharth Patel
Lead Architect
“Murmur is faster than paid cloud alternatives because it eliminates the network latency roundtrip entirely. Solid native engineering in Rust.”
Chloe Dubois
Product Manager
“The custom dictionary feature is essential for our proprietary APIs, microservice acronyms, and team names. Whisper recognizes them accurately every time.”
Devon Miller
Infrastructure Lead
“Attorney-client privilege cannot survive unvetted cloud audio streaming. Murmur's local air-gapped processing is the only dictation architecture our compliance committee cleared for confidential litigation briefs.”
Sarah Lin, Esq.
Partner, Tech IP Litigation
“Conducting frontier AI research means our unreleased papers and hypotheses are sensitive IP. Running whisper.cpp on an Apple M3 Max with zero telemetry allows me to dictate notes freely.”
Mateo Alvarez
ML Research Scientist
“Clinical therapy notes require absolute patient confidentiality. Knowing voice audio stays exclusively in RAM and vanishes upon paste gives me and my patients total peace of mind.”
Dr. Hannah Weiss
Clinical Psychologist
“Our security policy banned cloud transcription bots company-wide. Murmur passed our internal packet inspection and security audit with flying colors. 100% on-device is the future.”
Priya Nair
VP of Engineering
“Writing git commit messages, GitHub PR reviews, and technical documentation hands-free without any cloud lag has doubled my daily throughput. The shortcut is second nature now.”
Liam O'Connor
Senior Full-Stack Engineer
“Sub-180ms latency on Windows with an RTX 4080. It's the only dictation software that keeps pace with rapid market analysis and real-time trading journal entries without stutters.”
Alexander Chen
Quantitative Trader
Download Murmur. Free forever.
No credit card, account, or cloud telemetry required. Installs and runs in under 60 seconds.
macOS
Native Metal GPU acceleration on Apple Silicon (M1, M2, M3, M4) and Intel Macs. Runs quietly in your menu bar.
Windows
Native DirectML & CUDA acceleration for NVIDIA, AMD, and Intel GPUs. Operates seamlessly in your system tray.
Install via Command Line Package Managers
Frequently asked questions.
Everything you need to know about Murmur performance, privacy, and local architecture.