OpenAI's Whisper changed everything when it dropped in 2022. A single open-source model that could transcribe dozens of languages, handle accents, and run without a paid API. Developers have been building on it ever since.
But Whisper has a fundamental problem: it was designed for batch transcription, not live voice interfaces. Every transcription call processes a 30-second window — whether your audio is 2 seconds or 30. On a MacBook Pro, Whisper Large V3 takes 11,286ms to return a result. That's 11 seconds. For a live voice app, that's unusable.
Moonshine solves exactly this. With 107ms latency on the same MacBook Pro, and accuracy that beats Whisper Large V3 despite using 6x fewer parameters, it's the first ASR model genuinely built for real-time applications.
This post breaks down the full comparison — benchmarks, architecture, when to use each, and how to integrate Moonshine into your Python app today.
The Core Problem with Whisper for Real-Time Apps
Whisper's architecture uses a fixed 30-second input window. When you call it with a 3-second audio clip, it zero-pads the input to 30 seconds and runs the full encoder. You're paying the compute cost of 30 seconds of audio for 3 seconds of speech.
On constrained devices — edge hardware, Raspberry Pi, mobile — this makes Whisper impractical. On cloud servers it's expensive per call. And for interactive applications where you want to show text as the user speaks, it simply doesn't work.
Three specific gaps Whisper can't bridge for live voice:
- Fixed 30-second window — no look-ahead in live streams means enormous wasted compute on zero-padding
- No streaming caching — every call starts from scratch, even when 90% of the audio is the same as the previous call
- Poor edge language support — Whisper Base (the model that actually fits on edge devices) only achieves under-20% WER for 5 languages
Moonshine's Architecture: Built for Live Speech
Moonshine (now v2, released Feb 2026) was built from scratch by the team at Moonshine AI to solve these gaps. The v2 "streaming" models introduce three key improvements:
Flexible Input Windows
Moonshine processes exactly the audio you give it — no zero-padding. For a 3-second phrase, it only runs compute on 3 seconds. This alone produces a dramatic latency reduction compared to Whisper.
Streaming Caching
The most important innovation. Moonshine's streaming models cache the input encoding and part of the decoder state. When audio accumulates over time (as the user is still speaking), Moonshine reuses prior computation rather than starting over. This is how it achieves real-time transcription: the model does most of its work while the user is talking, so when the phrase ends, results arrive almost instantly.
Language-Specific Models
Rather than one multilingual model that's mediocre everywhere, Moonshine trains separate models per language. The result: dramatically better accuracy on Arabic, Korean, Japanese, Spanish, Vietnamese, and more — at model sizes that fit on edge devices.
Benchmark: Moonshine vs Whisper (2026)
These are the official benchmarks from Moonshine's GitHub, measured on MacBook Pro, Linux x86, and Raspberry Pi 5 — using CPU only (no GPU acceleration):
| Model | WER | Parameters | MacBook Pro | Linux x86 | R. Pi 5 |
|---|---|---|---|---|---|
| Moonshine Medium Streaming | 6.65% | 245M | 107ms | 269ms | 802ms |
| Whisper Large V3 | 7.44% | 1,500M | 11,286ms | 16,919ms | N/A |
| Moonshine Small Streaming | 7.84% | 123M | 73ms | 165ms | 527ms |
| Whisper Small | 8.59% | 244M | 1,940ms | 3,425ms | 10,397ms |
| Moonshine Tiny Streaming | 12.00% | 34M | 34ms | 69ms | 237ms |
| Whisper Tiny | 12.81% | 39M | 277ms | 1,141ms | 5,863ms |
The numbers tell a clear story:
- Moonshine Medium Streaming beats Whisper Large V3 on accuracy (6.65% vs 7.44% WER)
- Moonshine Medium Streaming is 105x faster on MacBook Pro (107ms vs 11,286ms)
- Moonshine Tiny runs on a Raspberry Pi at 237ms — Whisper Tiny takes 5,863ms on the same hardware
- Moonshine models run comfortably on Pi. Whisper Large V3 can't run on Pi at all
When to Use Moonshine vs Whisper
The short answer: use Moonshine for live voice, use Whisper (or FasterWhisper) for batch transcription.
Choose Moonshine when:
- You're building a voice assistant, voice command system, or real-time transcription UI
- Your target platform is edge hardware — mobile, IoT, Raspberry Pi, wearables
- You need transcription to start before the user finishes speaking (streaming display)
- Latency below 200ms is a hard requirement
- Privacy matters — all inference runs on-device, no data leaves the user's machine
- You need multi-language support with actual accuracy on non-English languages
Choose Whisper/FasterWhisper when:
- You're transcribing uploaded audio files, podcasts, or recorded meetings in bulk
- You have GPU infrastructure and want maximum throughput via batch processing
- You need the broadest language coverage (82 languages vs Moonshine's current 8)
- You're using cloud-based APIs where server latency hides the model's own latency
Moonshine Python Integration: Complete Example
Getting started with Moonshine for Python takes about 5 minutes:
pip install moonshine-voice
python -m moonshine_voice.download --language en
Basic live transcription from microphone
from moonshine_voice import MicTranscriber, TranscriptEventListener
class MyListener(TranscriptEventListener):
def on_line_text_changed(self, event):
# Called as the user is still speaking — real-time updates
print(f"\r{event.line.text}", end="", flush=True)
def on_line_completed(self, event):
# Called when speech pauses — final transcript for this phrase
print(f"\n✓ {event.line.text}")
transcriber = MicTranscriber(
model_path="/path/to/downloaded/model",
model_arch=1 # provided by download script
)
transcriber.add_listener(MyListener())
transcriber.start()
input("Press Enter to stop...\n")
transcriber.stop()
Transcribing a WAV file (non-streaming)
from moonshine_voice import Transcriber, TranscriptEventListener, load_wav_file
class FileListener(TranscriptEventListener):
def on_line_completed(self, event):
print(f"[{event.line.start_time:.1f}s] {event.line.text}")
transcriber = Transcriber(
model_path="/path/to/model",
model_arch=1
)
transcriber.add_listener(FileListener())
audio_data, sample_rate = load_wav_file("recording.wav")
transcriber.transcribe_without_streaming(audio_data, sample_rate)
Voice command recognition
from moonshine_voice import MicTranscriber, IntentRecognizer
from moonshine_voice import get_embedding_model
# Download embedding model for intent matching
embedding_path, embedding_arch = get_embedding_model("base")
recognizer = IntentRecognizer(
model_path=embedding_path,
model_arch=embedding_arch,
model_variant="q4",
threshold=0.75
)
def on_command(trigger, utterance, confidence):
print(f"Command '{trigger}' triggered ({confidence:.0%} confidence)")
# your app logic here
commands = ["turn on lights", "play music", "set timer for 5 minutes"]
for cmd in commands:
recognizer.register_intent(cmd, on_command)
transcriber = MicTranscriber(model_path="...", model_arch=1)
transcriber.add_listener(recognizer)
transcriber.start()
The intent recognizer uses semantic matching via a Gemma-300M embedding model — so "illuminate the room" will match "turn on lights" even though the words are different. This is a significant upgrade over keyword-based voice command systems.
Platform Support: Where Moonshine Runs
One of Moonshine's biggest practical advantages is a unified cross-platform library. The same API — same classes, same event system — runs across:
- Python —
pip install moonshine-voice, works on Mac/Linux/Windows - iOS/macOS — Swift Package Manager:
https://github.com/moonshine-ai/moonshine-swift/ - Android — Maven:
ai.moonshine:moonshine-voice - Raspberry Pi — optimized pip package, confirmed running at 237ms on Pi 5
- Windows — C++ library with Visual Studio support
- IoT/wearables — C++ core with OnnxRuntime backend
Whisper has excellent frameworks (FasterWhisper, whisper.cpp), but they're mostly optimized for desktop/server. Moonshine is the first ASR framework that was designed from the start to run identically across edge devices.
Speaker Identification and Diarization
Moonshine v2 includes built-in speaker identification using pyannote embeddings. When enabled (it's on by default), each transcript line gets a speaker_id and speaker_index:
class DiarizationListener(TranscriptEventListener):
def on_line_completed(self, event):
line = event.line
print(f"Speaker {line.speaker_index + 1}: {line.text}")
# Disable if you don't need it:
transcriber = Transcriber(
model_path="...",
model_arch=1,
options={"identify_speakers": "false"}
)
Whisper doesn't include native diarization — you'd need a separate pyannote or nemo pipeline. Moonshine bundles it.
Available Models and Accuracy
The current Moonshine model lineup (v0.0.49, Feb 2026):
- English Tiny — 26MB, 12.66% WER. Smallest possible footprint.
- English Tiny Streaming — 34MB, 12.00% WER. Tiny with streaming cache benefits.
- English Base — 58MB, 10.07% WER. Best balance of size and accuracy for non-streaming use.
- English Small Streaming — 123MB, 7.84% WER. Recommended for most live apps.
- English Medium Streaming — 245MB, 6.65% WER. Better than Whisper Large V3. Best for accuracy-critical apps.
- Other languages — Arabic, Japanese, Korean, Mandarin, Spanish, Ukrainian, Vietnamese (Base size, language-specific)
English models are MIT licensed. Non-English models use the Moonshine Community License (non-commercial). Commercial use of non-English models requires contacting Moonshine AI.
Moonshine vs Parakeet (Nvidia's ASR)
If you've been following ASR news, you've also seen Nvidia's Parakeet — a GPU-accelerated ASR model that achieves state-of-the-art accuracy on the HuggingFace OpenASR Leaderboard (sub-5% WER). The comparison:
- Parakeet: GPU-required, server-only, best for cloud transcription pipelines at scale. Excellent throughput with batch processing.
- Moonshine: CPU-first, edge-ready, purpose-built for real-time latency. Runs on Raspberry Pi.
These are different tools for different jobs. Parakeet wins on bulk cloud transcription. Moonshine wins on live edge applications.
ModelsLab Audio API: When You Don't Want to Self-Host
Self-hosting Moonshine makes sense when privacy or edge deployment is a hard requirement. But for cloud-based applications — transcription pipelines, async media processing, multi-tenant SaaS features — a managed API saves significant infrastructure work.
ModelsLab's Audio API provides production-ready speech-to-text and text-to-speech endpoints you can call from any language:
import requests
response = requests.post(
"https://modelslab.com/api/v6/voice/speech_to_text",
headers={"Content-Type": "application/json"},
json={
"key": "YOUR_API_KEY",
"url": "https://example.com/audio.wav",
"language": "en",
"model": "whisper",
"translate": False
}
)
data = response.json()
print(data["transcript"])
The API handles model management, scaling, and queuing — you just send audio and get transcripts back. See the ModelsLab API docs for full endpoint reference and language support.
The Bottom Line
If you're building a live voice application in 2026 — voice assistant, transcription overlay, voice command system — Moonshine is now the clear default choice:
- 107ms latency vs 11,286ms for Whisper Large V3 (on same hardware)
- Better accuracy than Whisper Large V3 with 6x fewer parameters
- Runs on Raspberry Pi and edge devices
- Streaming caching means transcription completes as the user finishes speaking
- Built-in speaker diarization, intent recognition, and cross-platform library
- MIT licensed (English models), active development (v0.0.49 in Feb 2026)
Whisper remains the right tool for batch processing, podcast transcription, and cloud pipelines where throughput matters more than latency. Both have their place.
Try Moonshine: pip install moonshine-voice and github.com/moonshine-ai/moonshine (5.8K stars, growing fast).
And if you need production audio API access without the infrastructure overhead, the ModelsLab Audio API offers managed speech-to-text with a simple REST interface.