GLM-TTS Technical Report
Abstract
This work proposes GLM-TTS, a production-level TTS system designed for efficiency, controllability, and high-fidelity speech generation. GLM-TTS follows a two-stage architecture, consisting of a text-to-token autoregressive model and a token-to-waveform diffusion model. With only 100k hours of training data, GLM-TTS achieves state-of-the-art performance on multiple open-source benchmarks. To meet production requirements, GLM-TTS improves speech quality through an optimized speech tokenizer with fundamental frequency constraints and a GRPO-based multi-reward reinforcement learning framework that jointly optimizes pronunciation, speaker similarity, and expressive prosody. In parallel, the system enables efficient and controllable deployment via parameter-efficient LoRA-based voice customization and a hybrid phoneme-text input scheme that provides precise pronunciation control. Our code is available at https://github.com/zai-org/GLM-TTS. Real-time speech synthesis demos are provided via Z.ai (audio.z.ai), the Zhipu Qingyan app/web (chatglm.cn).
Cite
@article{arxiv.2512.14291,
title = {GLM-TTS Technical Report},
author = {Jiayan Cui and Zhihan Yang and Naihan Li and Jiankun Tian and Xingyu Ma and Yi Zhang and Guangyu Chen and Runxuan Yang and Yuqing Cheng and Yizhi Zhou and Guochen Yu and Xiaotao Gu and Jie Tang},
journal= {arXiv preprint arXiv:2512.14291},
year = {2025}
}