# KRAFTON releases 1B zero-shot voice-cloning TTS

> Raon-OpenTTS-1B is a flow-matching diffusion transformer that clones English voices from short reference clips.

Published by The Open Weights on May 21, 2026. Canonical: https://theopenweights.com/news/raon-opentts-1b-mr3n

## Key facts

- Company: KRAFTON
- Model: Raon-OpenTTS-1B
- Version: 1.0
- Category: Text → Speech
- Modalities: Text → Speech
- License: Other (Open weights, commercial use allowed)
- Parameters: 1B
- Languages: English
- Significance: minor
- Published: 2026-05-21
- Last verified: 2026-08-25
- Hugging Face: https://huggingface.co/KRAFTON/Raon-OpenTTS-1B
- Canonical URL: https://theopenweights.com/news/raon-opentts-1b-mr3n

KRAFTON has published Raon-OpenTTS-1B, a one-billion-parameter text-to-speech model that generates English speech and can mimic a target voice from a short reference sample. The release is available on [Hugging Face](https://huggingface.co/KRAFTON/Raon-OpenTTS-1B) and marks the first version of the Raon open TTS line.

The model is a flow-matching diffusion transformer, an architecture that has become popular for high-quality audio and image synthesis because it can produce natural output in relatively few sampling steps. Positioned as a zero-shot voice-cloning system, it aims to reproduce a speaker's timbre without per-voice fine-tuning, relying instead on a reference clip at inference time.

## What it offers

- Roughly 1B parameters, a size that stays practical to run on a single modern GPU
- Zero-shot voice cloning from a short reference sample
- English-language output
- A flow-matching diffusion-transformer backbone

## Why it matters

Open zero-shot TTS remains a competitive space, and a compact 1B model that clones voices lowers the barrier for developers building narration, accessibility, and assistant features without training custom voices. The tradeoff is scope: this initial release targets English only, and the repository carries a non-standard "other" license, so teams should check the terms before commercial use. As a version 1.0, it establishes a baseline the family can iterate on.

## Get the model

- [Hugging Face](https://huggingface.co/KRAFTON/Raon-OpenTTS-1B)

## Sources

- [KRAFTON/Raon-OpenTTS-1B](https://huggingface.co/KRAFTON/Raon-OpenTTS-1B) — Hugging Face, May 21, 2026

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Source: The Open Weights (https://theopenweights.com/). Aggregated and written by Claude, curated by humans. Cite as: "KRAFTON releases 1B zero-shot voice-cloning TTS", The Open Weights, May 21, 2026, https://theopenweights.com/news/raon-opentts-1b-mr3n