hexgrad

hexgrad/Kokoro-82M

Kokoro is an open-weight TTS model with 82 million parameters. Despite its lightweight architecture, it delivers comparable quality to large...

Model Documentation

Kokoro is an open-weight TTS model with 82 million parameters. Despite its lightweight architecture, it delivers comparable quality to larger models while being significantly faster and more cost-efficient. With Apache-licensed weights, Kokoro can be deployed anywhere from production environments to personal projects.



🐈 GitHub: https://github.com/hexgrad/kokoro

🚀 Demo: https://hf.co/spaces/hexgrad/Kokoro-TTS

> [!NOTE] > As of April 2025, the market rate of Kokoro served over API is under $1 per million characters of text input, or under $0.06 per hour of audio output. (On average, 1000 characters of input is about 1 minute of output.) Sources: ArtificialAnalysis/Replicate at 65 cents per M chars and DeepInfra at 80 cents per M chars. > > This is an Apache-licensed model, and Kokoro has been deployed in numerous projects and commercial APIs. We welcome the deployment of the model in real use cases.

> [!CAUTION] > Fake websites like kokorottsai_com (snapshot: https://archive.ph/nRRnk) and kokorotts_net (snapshot: https://archive.ph/60opa) are likely scams masquerading under the banner of a popular model. > > Any website containing "kokoro" in its root domain (e.g. kokorottsai_com, kokorotts_net) is NOT owned by and NOT affiliated with this model page or its author, and attempts to imply otherwise are red flags.

  • Releases
  • Usage
  • EVAL.md ↗️
  • SAMPLES.md ↗️
  • VOICES.md ↗️
  • Model Facts
  • Training Details
  • Creative Commons Attribution
  • Acknowledgements


  • Releases



    | Model | Published | Training Data | Langs & Voices | SHA256 | | ----
  • | --------- | ------------- | -------------- | ------ |
  • | v1.0 | 2025 Jan 27 | Few hundred hrs | 8 & 54 | 496dba11 | | v0.19 | 2024 Dec 25 | <100 hrs | 1 & 10 | 3b0c392f |

    | Training Costs | v0.19 | v1.0 | Total | | -------------
  • | ----- | ---- | ----- |
  • | in A100 80GB GPU hours | 500 | 500 | 1000 | | average hourly rate | $0.80/h | $1.20/h | $1/h | | in USD | $400 | $600 | $1000 |

    Usage

    You can run this basic cell on Google Colab. Listen to samples. For more languages and details, see Advanced Usage.
    py
    !pip install -q kokoro>=0.9.2 soundfile
    !apt-get -qq -y install espeak-ng > /dev/null 2>&1
    from kokoro import KPipeline
    from IPython.display import display, Audio
    import soundfile as sf
    import torch
    pipeline = KPipeline(lang_code='a')
    text = '''
    Kokoro is an open-weight TTS model with 82 million parameters. Despite its lightweight architecture, it delivers comparable quality to larger models while being significantly faster and more cost-efficient. With Apache-licensed weights, Kokoro can be deployed anywhere from production environments to personal projects.
    '''
    generator = pipeline(text, voice='af_heart')
    for i, (gs, ps, audio) in enumerate(generator):
        print(i, gs, ps)
        display(Audio(data=audio, rate=24000, autoplay=i==0))
        sf.write(f'{i}.wav', audio, 24000)
    
    Under the hood, kokoro uses misaki, a G2P library at https://github.com/hexgrad/misaki

    Model Facts



    Architecture:
  • StyleTTS 2: https://arxiv.org/abs/2306.07691
  • ISTFTNet: https://arxiv.org/abs/2203.02395
  • Decoder only: no diffusion, no encoder release


  • Architected by: Li et al @ https://github.com/yl4579/StyleTTS2

    Trained by: @rzvzn on Discord

    Languages: Multiple

    Model SHA256 Hash: 496dba118d1a58f5f3db2efc88dbdc216e0483fc89fe6e47ee1f2c53f18ad1e4

    Training Details



    Data: Kokoro was trained exclusively on permissive/non-copyrighted audio data and IPA phoneme labels. Examples of permissive/non-copyrighted audio include:
  • Public domain audio
  • Audio licensed under Apache, MIT, etc
  • Synthetic audio[1] generated by closed[2] TTS models from large providers
  • [1] https://copyright.gov/ai/ai_policy_guidance.pdf
    [2] No synthetic audio from open TTS models or "custom voice clones"

    Total Dataset Size: A few hundred hours of audio

    Total Training Cost: About $1000 for 1000 hours of A100 80GB vRAM

    Creative Commons Attribution



    The following CC BY audio was part of the dataset used to train Kokoro v1.0.

    | Audio Data | Duration Used | License | Added to Training Set After | | ---------
  • | ------------- | ------- | --------------------------- |
  • | Koniwa tnc | <1h | CC BY 3.0 | v0.19 / 22 Nov 2024 | | SIWIS | <11h | CC BY 4.0 | v0.19 / 22 Nov 2024 |

    Acknowledgements



  • 🛠️ @yl4579 for architecting StyleTTS 2.
  • 🏆 @Pendrokar for adding Kokoro as a contender in the TTS Spaces Arena.
  • 📊 Thank you to everyone who contributed synthetic training data.
  • ❤️ Special thanks to all compute sponsors.
  • 👾 Discord server: https://discord.gg/QuGxSWBfQy
  • 🪽 Kokoro is a Japanese word that translates to "heart" or "spirit". It is also the name of an AI in the Terminator franchise.


  • kokoro

    Files & Weights

    FilenameSizeAction
    kokoro-v1_0.pth 0.30 GB