Model reference · open weights
Zonos-hybrid is an open-weight audio or speech model from Zyphra. AxForge deploys and operates it for you on dedicated EU-owned hardware — with the licence handled where one is required.
Available as managed deployment — configured and operated for you on dedicated EU hardware, quoted per deployment.
What it is
| Released by | Zyphra |
|---|---|
| Type | Audio & music |
| Task | Text→speech |
| Parameters (lead) | 1.7B |
| Runs with | zonos |
| Released | 2025-02-06 |
| Popularity | 1k downloads / month |
| Licence | Open weights |
About
alt="Title card" style="width: 500px; height: auto; object-position: center top;">
Zonos-v0.1 is a leading open-weight text-to-speech model trained on more than 200k hours of varied multilingual speech, delivering expressiveness and quality on par with—or even surpassing—top TTS providers.
Our model enables highly natural speech generation from text prompts when given a speaker embedding or audio prefix, and can accurately perform speech cloning when given a reference clip spanning just a few seconds. The conditioning setup also allows for fine control over speaking rate, pitch variation, audio quality, and emotions such as happiness, fear, sadness, and anger. The model outputs speech natively at 44kHz.
Zonos follows a straightforward architecture: text normalization and phonemization via eSpeak, followed by DAC token prediction through a transformer or hybrid backbone. An overview of the architecture can be seen below.
alt="Architecture diagram"
style="width: 1000px;
height: auto;
object-position: center top;">
import torch
import torchaudio
from zonos.model import Zonos
from zonos.conditioning import make_cond_dict
model = Zonos.from_pretrained("Zyphra/Zonos-v0.1-hybrid", device="cuda")
# model = Zonos.from_pretrained("Zyphra/Zonos-v0.1-transformer", device="cuda")
wav, sampling_rate = torchaudio.load("assets/exampleaudio.mp3")
speaker = model.make_speaker_embedding(wav, sampling_rate)
cond_dict = make_cond_dict(text="Hello, world!", speaker=speaker, language="en-us")
conditioning = model.prepare_conditioning(cond_dict)
codes = model.generate(conditioning)
wavs = model.autoencoder.decode(codes).cpu()
torchaudio.save("sample.wav", wavs[0], model.autoencoder.sampling_rate)
uv run gradio_interface.py
# python gradio_interface.py
This should produce a sample.wav file in your project root directory.
For repeated sampling we highly recommend using the gradio interface instead, as the minimal example needs to load the model every time it is run.
At the moment this repository only supports Linux systems (preferably Ubuntu 22.04/24.04) with recent NVIDIA GPUs (3000-series or newer, 6GB+ VRAM).
See also Docker Installation
Zonos depends on the eSpeak library phonemization. You can install it on Ubuntu with the following command:
apt install -y espeak-ng
We highly recommend using a recent version of uv for installation. If you don't have uv installed, you can install it via pip: pip install -U uv.
uv sync
uv sync --extra compile
uv pip install -e .
uv pip install -e .[compile]
pip install -e .
pip install --no-build-isolation -e .[compile]
For convenience we provide a minimal example to check that the installation works:
uv run sample.py
# python sample.py
git clone https://github.com/Zyphra/Zonos.git
cd Zonos
# For gradio
docker compose up
# Or for development you can do
docker build -t Zonos .
docker run -it --gpus=all --net=host -v /path/to/Zonos:/Zonos -t Zonos
cd /Zonos
python sample.py # this will generate a sample.wav in /Zonos
If you find this model useful in an academic context please cite as:
@misc{zyphra2025zonos,
title = {Zonos-v0.1: An Expressive, Open-Source TTS Model},
author = {Dario Sucic, Mohamed Osman, Gabriel Clark, Chris Warner, Beren Millidge},
year = {2025},
}From the published model card. Full card on the HuggingFace links in the sidebar.
How it works
Using it via the API
Once AxForge deploys zonos-hybrid for you, it answers on the OpenAI-compatible API — the same base URL and keys as every other model. (zonos-hybrid below is illustrative; you get the exact model name on deployment.)
$ curl -sS https://api.axforge.ai/v1/audio/transcriptions \ -H "Authorization: Bearer $AXFORGE_API_KEY" \ -F model="zonos-hybrid" -F file=@audio.mp3
Create an account — your API key is available in the console. 3M free tokens every 30 days with every new account.