MOSS-TTS-Nano
Demo ↗
Text-to-Speech Voice Cloning Multilingual Apr 10, 2026

MOSS-TTS-Nano

A multilingual tiny speech generation model for realtime voice cloning, CPU-friendly deployment, and lightweight product integration.

Parameters

~100 M

Audio Supported

48 kHz Stereo

Authors

OpenMOSS Team

Affiliations

Fudan NLP Lab · MOSI.AI


MOSS-TTS-Nano is a deployment-first TTS model designed for realtime speech generation, voice cloning, and lightweight integration. Built on an Audio Tokenizer + LLM autoregressive pipeline, it stays compact enough for practical CPU use while covering Chinese, English, and a broad multilingual set.

The model pairs a ~20M-parameter MOSS-Audio-Tokenizer-Nano with a small LLM for autoregressive token prediction. The tokenizer uses a CNN-free, causal Transformer design with RVQ 16 codebooks operating at a 12.5 Hz token stream — achieving 0.125–2 kbps variable bitrate while preserving 48 kHz stereo output quality. Voice cloning is driven entirely by a short reference clip, with no additional fine-tuning required.

Key Features

Model Size

0.1 B

Compact enough for practical CPU inference — no GPU required.

Audio Quality

48 kHz Stereo

Native 2-channel input and output at full 48 kHz sample rate.

Languages

20

Mandarin, English, Japanese, Korean, Spanish, French, and more.

Tiny Tokenizer

~20 M params

CNN-free, causal Transformer with RVQ 16 codebooks at 12.5 Hz.

Bitrate

0.125–2 kbps

Variable bitrate via configurable codebook count.

Inference

Realtime

Streaming with low first-token latency. Long text auto-chunked.

Architecture

Following the MOSS-TTS technical report, the family-level design is organized as discrete audio tokens + autoregressive modeling + large-scale pretraining. This Nano demo keeps the same recipe in a smaller, deployment-first configuration.

MOSS-TTS-Nano Audio Tokenizer architecture: 48 kHz stereo input through Causal Transformers, RVQ 16 bottleneck, decoder, and Discriminator

The architecture of MOSS-Audio-Tokenizer-Nano


MOSS-Audio-Tokenizer

The tokenizer is a causal Transformer audio codec that compresses 48 kHz stereo audio into a 12.5 fps RVQ token stream for scalable autoregressive modeling. In the report, the encoder and decoder each contain 12 causal Transformer blocks with sliding-window attention, and the quantizer uses 16 RVQ layers so the token sequence remains compact enough for long-context generation.

20M params 48kHz stereo 16-layer RVQ

MOSS-TTS-Nano Architecture

The architecture of MOSS-TTS-Nano

MOSS TTS Nano

On top of the tokenizer, MOSS-TTS-Nano can adopt a hierarchical token modeling design built around a Local Transformer. Instead of using RVQ-aware temporal delays, the model sums the embeddings from all RVQ layers at each aligned time step and feeds that hidden state into a single Transformer backbone. The backbone then produces one global latent per step, which a lightweight autoregressive Local Transformer expands into the within-step token block, sequentially predicting one text-or-pad token and 16 RVQ audio tokens.

100 M params Local Transformer Tiny, Fast and Powerful

Demo

Language Coverage

Japanese, Korean, Spanish, French, German, Italian, Hungarian, Russian, Persian, Arabic, Polish, Portuguese, Czech, Danish, Swedish, Greek, and Turkish — grouped with Chinese and English.