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Voxtral TTS - Mistral AI's open-source text-to-speech model

Voxtral TTS is an open-source text-to-speech model from Mistral AI, based on a 4 billion parameter architecture and supporting 9 languages. The model boasts an ultra-low latency of 90 milliseconds and a 6x real-time generation speed, capable of generating text from just 3-5 seconds of audio...

What is Voxtral TTS?

Voxtral TTS is an open-source text-to-speech model from Mistral AI, based on a 4 billion parameter architecture and supporting 9 languages. The model boasts an ultra-low latency of 90 milliseconds and a 6x faster real-time generation speed, achieving zero-sample speech cloning with only 3-5 seconds of audio. The model can be deployed on edge devices, requiring only 3GB of memory after quantization, and its API is priced at $0.016 per thousand characters. Voxtral TTS completes Mistral's end-to-end voice AI platform, suitable for scenarios such as voice customer service, real-time translation, and audiobooks, and outperforms competitor ElevenLabs in multiple evaluations.

Main functions of Voxtral TTS

  • Multilingual speech synthesisIt supports text-to-speech generation in nine languages: English, French, German, Spanish, Dutch, Portuguese, Italian, Hindi, and Arabic.
  • Zero-sample speech cloningIt only requires 3-5 seconds of reference audio to clone the voice of any speaker and supports cross-language timbre transfer.
  • Emotional style controlThe model can adjust the emotional state (such as anger, happiness, sadness) and parameters such as speech rate, tone, and volume of the generated speech.
  • Ultra-low latency real-time generationThe initial audio time is only 90 milliseconds, and the real-time factor is 6 times that of real-time dialogue scenarios.
  • End-side equipment deploymentThe model can run on edge devices such as smartwatches and mobile phones, and requires only about 3GB of memory after quantization.

Voxtral TTS Technical Principles

  • Three-module cascaded architectureThe model consists of a Transformer language model with 3.4B parameters, a stream-matching acoustic model with 390M parameters, and a neural audio codec with 300M parameters, with a total of approximately 4 billion parameters.
  • Text to Discrete RepresentationBased on the Ministral 3B backbone network, a streaming BERT-style masked language model is used to convert the input text into discrete speech tokens.
  • Stream matching spectrum generationThe model uses flow matching technology to replace the traditional diffusion model, which quickly converts discrete tokens into continuous Mel spectrograms, achieving faster inference speed.
  • Neural audio encoding and decodingThe spectrogram is reconstructed into a high-quality audio waveform using a 300M parameter codec, ensuring the naturalness of the output.
  • Edge-optimized deploymentSupports INT8/INT4 quantization compression, reducing model size to 3GB memory usage, and adapting to running on edge devices such as smartphones.

Key information and usage requirements of Voxtral TTS

  • Release timeOfficially released by Mistral AI on March 26, 2026.
  • Model sizeThe total number of parameters is approximately 4 billion, including a 3.4B Transformer language model, a 390M stream-matching acoustic model, and a 300M neural audio codec.
  • Supported languagesThe languages are: English, French, German, Spanish, Dutch, Portuguese, Italian, Hindi, and Arabic, totaling nine languages.
  • Performance indicatorsThe initial audio time is 90 milliseconds, the real-time factor is 6 times, and voice cloning only requires 3-5 seconds of reference audio.
  • LicenseOpen source weights are licensed under the Creative Commons license, and the API is priced at $0.016 per thousand characters.
  • Hardware RequirementsLocal deployment requires at least 3GB of memory (quantized version), and supports edge devices such as smartwatches, smartphones, and laptops.

Voxtral TTS's core advantages

  • Open source and customizableThe model weights are completely open source, allowing enterprises to deploy them locally and fine-tune them as needed, thus avoiding the data privacy risks associated with relying on third-party cloud services.
  • Ultra-low latency and high performanceThe initial audio time is only 90 milliseconds, and the real-time factor is 6 times higher, which is significantly better than similar competing products and meets the needs of real-time dialogue scenarios.
  • End-side deployment capabilityAfter quantization, it only requires 3GB of memory and can run on edge devices such as smartphones and smartwatches without cloud connectivity.
  • Zero-sample speech cloningIt can clone the voice of any speaker with only 3-5 seconds of audio, supports cross-language timbre transfer, and greatly reduces the cost of voice customization.

How to use Voxtral TTS

  • Online experienceTo generate audio, simply access the Mistral Studio console or the Le Chat platform, enter text, and select the voice parameters.
  • API callsRegister a Mistral account to obtain an API key, send text and an optional reference audio URL via the REST API, and receive the generated audio file.
  • Open source local deploymentDownload model weights from Hugging Face, load them using the PyTorch or transformers library, and run inference on your local GPU or CPU.

Voxtral TTS project address

  • Project official websitehttps://mistral.ai/news/voxtral-tts
  • HuggingFace model libraryhttps://huggingface.co/mistralai/Voxtral-4B-TTS-2603
  • Technical Papers: https://mistral.ai/static/research/voxtral-tts.pdf

Comparison of Voxtral TTS with similar competitors

Dimension Voxtral TTS ElevenLabs OpenAI TTS
open source Completely open source, can be deployed locally Closed source, API only Closed source, API only
Latency performance 90ms initial audio, 6 times faster real-time Flash v2.5 has lower latency. Medium latency
Voice cloning 3-5 second zero-sample cloning Support, leading results Limited support
Pricing $0.016/thousand characters higher price Pay-per-use
Deployment method Cloud API + local edge device Cloud API only Cloud API only

Application scenarios of Voxtral TTS

  • Real-time voice interactionThe model supports the construction of low-latency intelligent customer service, voice assistants, and chatbots, achieving natural human-computer dialogue with a 90-millisecond response time.
  • Cross-language content localizationIt translates video, podcast, and other content into nine target languages while preserving the original speaker's vocal characteristics, thus reducing the cost of multilingual production.
  • Personalized audio contentThe model can clone specific voices to generate audiobooks, news broadcasts, and educational training audio, meeting the customized needs of brands.
  • Immersive entertainment experienceProvides emotionally controllable dynamic voices for game NPCs and interactive narratives, enhancing player immersion.
  • Accessibility toolsIt can read text messages aloud to visually impaired users or reconstruct personalized digital voices for people with speech impairments.