Overview
OpenWhispr supports two local transcription engines for completely private, offline speech-to-text:- Whisper (via whisper.cpp) - Multiple model sizes with quality/speed tradeoffs
- Parakeet (via sherpa-onnx) - NVIDIA’s multilingual ASR model with fast CPU inference
Local models keep your voice data completely private - audio never leaves your device.
Whisper Models
Whisper models use the GGML format and are downloaded from HuggingFace.Available Whisper Models
- tiny
- base
- small
- medium
- large
- turbo
Size: ~75MBSpeed: FastestQuality: Lower accuracy, good for simple dictationRecommended for: Quick notes, low-end hardwareFile:
ggml-tiny.binModel Characteristics
| Model | Size | Quality | Speed | Use Case |
|---|---|---|---|---|
| tiny | 75MB | ⭐⭐ | ⚡⚡⚡⚡⚡ | Quick notes |
| base | 142MB | ⭐⭐⭐ | ⚡⚡⚡⚡ | General use |
| small | 466MB | ⭐⭐⭐⭐ | ⚡⚡⚡ | Professional |
| medium | 1.5GB | ⭐⭐⭐⭐ | ⚡⚡ | High quality |
| large | 3GB | ⭐⭐⭐⭐⭐ | ⚡ | Best quality |
| turbo | 1.6GB | ⭐⭐⭐⭐⭐ | ⚡⚡⚡ | Quality + speed |
NVIDIA Parakeet Models
Parakeet models use ONNX format with INT8 quantization for efficient CPU inference.Available Parakeet Models
- parakeet-tdt-0.6b-v3
Size: ~680MBLanguages: 25 languages with auto-detectionSpeed: Very fast on CPUQuality: Comparable to Whisper small/baseSupported Languages:
- Bulgarian, Croatian, Czech, Danish, Dutch
- English, Estonian, Finnish, French, German
- Greek, Hungarian, Italian, Latvian, Lithuanian
- Maltese, Polish, Portuguese, Romanian, Slovak
- Slovenian, Spanish, Swedish, Russian, Ukrainian
encoder.int8.onnxdecoder.int8.onnxjoiner.int8.onnxtokens.txt
Downloading Models Through the UI
Select and Download Model
For Whisper:
- Choose a model size (tiny, base, small, medium, large, turbo)
- Click Download
- Wait for download to complete (progress bar shows status)
- Select
parakeet-tdt-0.6b-v3 - Click Download
- Wait for download and extraction
Storage Locations
Models are stored in the OpenWhispr cache directory:- macOS
- Windows
- Linux
Whisper models:Parakeet models:
Model Directory Structure
Whisper:Model Cleanup and Disk Space Management
Deleting Individual Models
Removing All Models
Manual Cleanup
You can also manually delete model files from the cache directory:- macOS/Linux
- Windows
Choosing Between Whisper and Parakeet
Use Whisper When:
- You need multiple model sizes to balance quality and speed
- You’re transcribing English primarily
- You want the best possible accuracy (large/turbo models)
- You have a GPU and want CUDA acceleration (if enabled)
Use Parakeet When:
- You need multilingual support (25 languages)
- You want fast CPU inference without GPU
- You’re on lower-end hardware
- You prefer a single, well-optimized model
Performance Optimization
Hardware Acceleration
Whisper CUDA Support (Experimental): If you have an NVIDIA GPU, you can enable CUDA acceleration:CUDA support requires compatible NVIDIA drivers and CUDA toolkit installation.
Pre-warming Models
OpenWhispr pre-warms models on startup to eliminate cold-start delays:- Whisper: Server starts when you select a model
- Parakeet: Server pre-warms if
LOCAL_TRANSCRIPTION_PROVIDER=nvidia
Troubleshooting
Download Failed or Incomplete
Download Failed or Incomplete
Symptoms: Download stops partway through or model doesn’t workSolutions:
- Check your internet connection
- Ensure you have enough disk space (model size × 2.5 for extraction)
- Try downloading again - OpenWhispr resumes interrupted downloads
- Check the logs for specific error messages
- Manually delete partial files and retry:
Model Not Found Error
Model Not Found Error
Symptoms: Error saying model isn’t downloaded when it should beSolutions:
- Verify the model file exists in the cache directory
- Check file permissions (should be readable by your user)
- For Parakeet, ensure all 4 required files exist:
encoder.int8.onnxdecoder.int8.onnxjoiner.int8.onnxtokens.txt
- Try re-downloading the model
Transcription Slow or Hangs
Transcription Slow or Hangs
Symptoms: Transcription takes a long time or appears to freezeSolutions:
- For Whisper: Try a smaller model (base instead of large)
- For Parakeet: Ensure sherpa-onnx binary is accessible
- Check CPU usage - high background activity may slow processing
- For very long recordings, consider splitting into shorter clips
- Check the logs for server timeout errors
Out of Disk Space
Out of Disk Space
Symptoms: Download fails with disk space errorSolutions:
- Free up disk space (models need 2.5× their size for extraction)
- Use the model cleanup feature to remove unused models
- Choose a smaller model:
- Try
baseinstead oflarge(save ~2.8GB) - Use Parakeet instead of multiple Whisper models
- Try
Model Registry Data
All model metadata is defined insrc/models/modelRegistryData.json:
This centralized registry ensures consistency across the app and makes it easy to add new models in the future.