Side by side
CMU Sphinx vs ESPnet
Both stand on speech recognition software. Which one you can start free with, which one lets you read the code, and what each costs once you pay.
Free plan AndroidLinuxMac+2
CMU Sphinx offers speech-recognition components and model-training tools for developers, with documented offline and on-device options. Users need to prepare models and PCM audio, and Android users should note the tutorial's age-related warning.
Visit CMU Sphinx
Free plan Open source APILinuxMac+2
Choose ESPnet for an open-source speech toolkit with broad task coverage, recipes, and pretrained-model inference options. It can also support training, though that requires additional dependencies. Look elsewhere if you need voice cloning, which ESPnet does not support.
Visit ESPnetThe facts
| CMU Sphinx | ESPnet | |
|---|---|---|
| Free plan | Yes | Yes |
| Open source | Not published | Yes |
| Runs on | Android, Linux, Mac, Self-hosted, Windows | API, Linux, Mac, Self-hosted, Windows |
| Lowest paid plan | Free or on request | Free or on request |
| Plans published | 1 | 2 |
| Maker | Not published | ESPnet |
| Website | cmusphinx.github.io | espnet.github.io |
| On speech recognition software | #3 of 32 | #1 of 32 |
CMU Sphinx: what it does well
- Open-source BSD-like license permits commercial distribution.
- Supports keyword spotting and word-level segmentation.
- Designed for efficient recognition on low-resource platforms.
- Offline and on-device use are documented.
What to know first
- Recognition requires acoustic and language models.
- Audio must be converted to PCM before processing.
- The Android tutorial may not work with current tools.
- Large-vocabulary recognition is too demanding for small devices.
ESPnet: what it does well
- Covers recognition, synthesis, translation, and enhancement tasks.
- Provides complete recipes for a range of speech tasks.
- Published models can run in CPU or GPU containers.
- Commercial use is permitted under Apache License 2.0.
- Offers API access and WAV export.
What to know first
- Training requires a separate extra with multiple dependencies.
- Some task-specific packages require separate installation.
- ESPnet 1 is no longer supported.
Alternatives to CMU Sphinx Alternatives to ESPnet The whole list