supertonic-3

**Supertonic** is a lightweight text-to-speech system for local inference. It runs with ONNX Runtime entirely on your device, with no cloud call required for synthesis. **Supertonic 3** expands the open-weight release from 5 to **31 languages**, improves reading stability, and reduces repeat/skip failures. Install the Python SDK and generate speech immediately. On first run, the SDK downloads the model assets from Hugging Face. pip install supertonic from supertonic import TTS tts = TTS(auto_download=True) style = tts.get_voice_style(voice_name="M1") text = "A gentle breeze moved through the open window while everyone listened to the story." wav, duration = tts.synthesize(text, voice_style=style, lang="en") tts.save_audio(wav, "output.wav") print(f"Generated {duration:.2f}s of audio") - **31 languages**: expanded from the 5-language Supertonic 2 release. - **More stable reading**: fewer repeat and skip failures, especially on short and long utterances. - **Higher speaker similarity**: improved similarity across the shared-language set compared with Supertonic 2. - **Expression tags**: supports simple tags such as `<laugh>`, `<breath>`, and `<sigh>`. The open-weight package includes fixed preset voice styles for immediate local inference. If you want to hear how Supertonic 3 performs with zero-shot custom voice styles, visit the [Audio Sample Demo](https://supertonic3.github.io/) to compare reference audio and generated speech across several use cases. To create your own Supertonic 3 voice-style JSON from reference audio, use [Supertonic Voice Builder](https://supertonic.supertone.ai/voice-builder); purchased Voice Builder styles include downloadable embeddings for both Supertonic 2 and Supertonic 3. Here are a few reference/generated pairs from the audio sample demo: **Call center, English** Text: Good morning, thank you for calling. How can I help you today? **Character voice, Japanese** Text: ふふっ、退屈してたところなの。ちょうどいい遊び相手、見つけたかも♪ **Elder character voice, Korean** Text: 혼자 떠나기엔 길이 험하구나. 이 낡은 검을 가져가거라. 언젠가 어둠이 네 이름을 부르더라도, 부디 빛을 잊지 말거라. **Audiobook, English** Text: I was not afraid of silence. I had lived with it long enough to know that, sometimes, it speaks more honestly than people do. **Audiobook, Japanese** Text: その朝、ロンドンの霧はいつになく低く垂れこめていた。私はただの訪問者だと思っていたが、ホームズの目はすでに別の結論にたどり着いていた。 **News, English** Text: Here’s a story worth paying attention to. Supertone has released Supertonic 3, its on-device TTS model. This version expands support to thirty-one languages and improves reading stability. Supertonic 3 is designed for practical on-device inference: compact enough to run locally, while staying competitive with much larger open TTS systems. Across measured languages, Supertonic 3 stays within a competitive WER/CER range against much larger open TTS models such as VoxCPM2, while preserving a lightweight on-device deployment path. Asterisked languages use CER; the others use WER. Compared with Supertonic 2, Supertonic 3 reduces repeat and skip failures, improves speaker similarity across the shared-language set, and expands language coverage from 5 to 31 languages. Supertonic 3 runs fast on CPU, even compared with larger baselines measured on A100 GPU, and uses substantially less memory. It does not require a GPU, which makes local, browser, and edge deployment much easier. At about 99M parameters across the public ONNX assets, Supertonic 3 is much smaller than 0.7B to 2B class open TTS systems. The smaller model size is a practical advantage for download size, startup time, and on-device inference. This project's sample code is released under the MIT License. See the [GitHub repository](https://github.com/supertone-inc/supertonic) for details. The accompanying model is released under the OpenRAIL-M License. See the [LICENSE](https://huggingface.co/Supertone/supertonic-3/blob/main/LICENSE) file in this repository for details. This model was trained using PyTorch, which is licensed under the BSD 3-Clause License but is not redistributed with this project. See the [PyTorch license](https://docs.pytorch.org/FBGEMM/general/License.html) for details. Copyright (c) 2026 Supertone Inc.