whatmodel.sh / tts / MOSS-TTS v1.5 (8B)

MOSS-TTS v1.5 (8B) is an open-weights text-to-speech model from OpenMOSS, released May 2026. Its published size is 8.49B parameters. Licence: apache-2.0.

Catalogue identity notes

OpenMOSS-Team/MOSS-TTS-v1.5 (MossTTSDelay-8B; 8,489,841,664 parameters per HF safetensors metadata). Distinct from MOSS-TTSD dialogue models.

63.2±1.5#26 of 118 text-to-speech modelsfrom 16 benchmark results across 4 sources

Score within the Vapi Humanness · Bradley–Terry rating, 2026-09-25 snapshot comparison set only.

$ how it compares

The text-to-speech models ranked either side of MOSS-TTS v1.5 (8B), out of 148 with a score.

#modelscorewhereRAMreleased
31Fish Audio S2.1 Pro Fish Audio63±3api $15.00/M chars2026-06
32IndexTTS-2 IndexTeam (bilibili)63±1local~8.9GB2025-09
33MOSS-TTS v1.5 (8B) OpenMOSS63±2local~24GB2026-05
34GLM-TTS Z.ai63±2local~8.9GB2025-12
35Sonic 3.5 Cartesia63±2comparison only2026-05

see all text-to-speech models · find the ones that fit your machine

$ what it's good at

voice cloning▁·▁▁▁▁▁▁▇█▃▃ #22 of 37 · 45% of its score · 6 tests

Beats Gemini 3.1 Flash TTS Preview here, though they rank higher overall. Trails E2 TTS Base (F5-TTS reproduction), DMOSpeech 2, Qwen3-TTS 12Hz 0.6B Base here, though they rank lower overall.

testresultvs the others in its rundifficultycountswhy
Seed-TTS test-en · speaker similarity (WavLM-large SV)68.0% ✎█·█·██·▄·▄·▄ beats 3/10medium · avg 53%▇▇▇▇▇ 11%at its level
Seed-TTS test-zh · speaker similarity (WavLM-large SV)76.1% ✎▃··▃█▅▅··▃·▃ beats 4/10medium · avg 62%▇▇▇▇ 11%typical
Seed-TTS-Eval · test-en/test-zh macro mean error1.7% ✎▄··▄▄····█▄▄ beats 1/6avg 3.7%▇▇▇ 7.5%typical
MiniMax multilingual test set · 21-language mean error (UltraEval-Audio common set)5.9% ✎█··█·····█·█ beats 2/3avg 18%▇▇ 6.2%typical
Seed-TTS test-en · Whisper large-v3 WER +12.7% ✎▃··▃▅··▅·█▃▅ beats 1/11avg 3.6%▇▇ 4.8%blunt · several runs
Seed-TTS test-zh · Paraformer CER +11.5% ✎▃··▄··▂▂█·▄▂ beats 0/11avg 2.1%▇▇ 3.8%blunt
other tests9 not in a task · 54% of its score
testresultvs the others in its rundifficultycountswhy
CV3-Eval hard-en · WER6.4% ✎█··██·██████ beats 8/8avg 26%▇▇▇▇▇▇ 15%sharp
CV3-Eval ZH (zero-shot Chinese) · CER3.9% ✎█▄···█▄·█··▄ beats 2/8avg 9.2%▇▇▇▇▇ 12%typical
CV3-Eval hard-zh · CER8.4% ✎▃▃·▃··▃▃█··▃ beats 5/8avg 23%▇▇▇▇ 9.4%typical
CV3-Eval hard-en · speaker similarity (ERes2Net SV)66.4% ✎▄█▄·▄··▄··▄█ beats 2/8medium · avg 49%▇▇▇▇ 8.8%at its level
CV3-Eval EN (zero-shot English) · WER5.5% ✎▃·······▃▅█▅ beats 4/8avg 16%▇▇ 3.8%noisy
RVCBench LibriTTS clean voice cloning · ECAPA speaker similarity57.0% ✎▃·····▂▂▂▃█▆ beats 10/15medium · avg 46%▇ 3.2%blunt · at its level
MiniMax multilingual test set · 23-language mean error3.8% ✎▃·▃·▃·····▃█ beats 4/6avg 44%▇ 1.6%sharp · noisy
CV3-Eval multilingual voice clone · 9-language mean error6.1% ✎▃·····▃···▅█ beats 3/6avg 20%▇ 1.2%noisy
1 more test
testresultvs the others in its rundifficultycountswhy
RVCBench LibriTTS clean voice cloning · Whisper-medium WER6.0% ✎▂▂▂··▂·▃▃▃█▂ beats 9/15avg 8.6%▇ 0.0%blunt · noisy

$ where to run it

Other ways to run it

version

  1. Run it as published · needs ~24.08 GB · from huggingface.co/OpenMOSS-Team (official)
    conda create -n moss-tts python=3.12 -y && conda activate moss-tts && git clone https://github.com/OpenMOSS/MOSS-TTS.git && cd MOSS-TTS && pip install --extra-index-url https://download.pytorch.org/whl/cu128 -e . && python -c "import torch, torchaudio; from transformers import AutoModel, AutoProcessor; torch.backends.cuda.enable_cudnn_sdp(False); pretrained_model_name_or_path = 'OpenMOSS-Team/MOSS-TTS-v1.5'; device = 'cuda' if torch.cuda.is_available() else 'cpu'; dtype = torch.bfloat16 if device == 'cuda' else torch.float32; attn_implementation = 'sdpa' if device == 'cuda' else 'eager'; processor = AutoProcessor.from_pretrained(pretrained_model_name_or_path, trust_remote_code=True); processor.audio_tokenizer = processor.audio_tokenizer.to(device); model = AutoModel.from_pretrained(pretrained_model_name_or_path, trust_remote_code=True, attn_implementation=attn_implementation, torch_dtype=dtype).to(device); model.eval(); torch.set_grad_enabled(False); batch = processor([[processor.build_user_message(text='We stand on the threshold of the AI era.')]], mode='generation'); outputs = model.generate(input_ids=batch['input_ids'].to(device), attention_mask=batch['attention_mask'].to(device), max_new_tokens=4096); [torchaudio.save('sample{}.wav'.format(i), m.audio_codes_list[0].unsqueeze(0), processor.model_config.sampling_rate) for i, m in enumerate(processor.decode(outputs))]"

Official weights and documentation: huggingface.co/OpenMOSS-Team ↗

$ how the score was worked out · UltraEval-Audio (OpenBMB) · T… 85%, Higgs Audio v3 comparison tab… 10%, RVCBench: Benchmarking Robust… 3% and 1 more

Each result implies a score on its own, after adjusting for how hard its test is and who ran it. The score is their weighted average, with a small pull toward the middle for thinly tested models. Each test's weight is its counts column above; here it's added up by who ran the tests. How it works

not counted (1)

SGLang-Omni serving cookbooks (SGLang-Omni team measurements)Seed-TTS test-zh · Paraformer CER [correct]1.4%the only model in this source's run of the test, so there is nothing to compare it with there; another run of the test counts

$ improve this page

Use a short GitHub form or edit the data through a pull request. Every number needs a source; here's which ones we can use.

data updated · sources and licences · json