End-to-End On-Device Quantization-Aware Training for LLMs at Inference Cost

Qitao Tan, Xiaoying Song, Ningxi Cheng, Guoming Li, Jun Liu, Lingzi Hong, Caiwen Ding, Jundong Li, Xiaoming Zhai, Shaoyi Huang, Jin Lu, Ninghao Liu, Wei Niu, Geng Yuan


Abstract
Quantization reduces the deployment cost of large language models (LLMs). However, post-training quantization (PTQ) cannot fine-tune model parameters and often degrades accuracy in low-bit settings, while quantization-aware training (QAT) requires backpropagation and incurs high memory overhead. We propose ZeroQAT, a zeroth-order QAT framework supporting both weight and activation quantization. By using forward-only gradient estimation, ZeroQAT removes backpropagation and substantially reduces memory and computation while retaining end-to-end optimization benefits. We further introduce a lightweight variant of ZeroQAT for quantized fine-tuning, which freezes and pre-quantizes most parameters to further cut memory usage. Experiments show that ZeroQAT consistently outperforms representative PTQ and QAT baselines while requiring significantly less memory. For example, ZeroQAT enables fine-tuning of a 13B model at extremely low bit-widths (e.g., 2-4 bits) on a single 8GB GPU, and even allows fine-tuning a 6.7B model on a OnePlus 12 smartphone, demonstrating its practicality for end-to-end QAT on resource-limited edge devices.
Anthology ID:
2026.findings-emnlp.28
Volume:
Findings of the Association for Computational Linguistics: EMNLP 2026
Month:
October
Year:
2026
Address:
Budapest, Hungary
Editors:
Hung-Yi Lee, Sunipa Dev, Jessy Li, Desmond Elliott
Venue:
Findings
SIG:
SIGDAT
Publisher:
Association for Computational Linguistics
Note:
Pages:
556–577
Language:
URL:
https://aclanthology.org/2026.findings-emnlp.28/
DOI:
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Cite (ACL):
Qitao Tan, Xiaoying Song, Ningxi Cheng, Guoming Li, Jun Liu, Lingzi Hong, Caiwen Ding, Jundong Li, Xiaoming Zhai, Shaoyi Huang, Jin Lu, Ninghao Liu, Wei Niu, and Geng Yuan. 2026. End-to-End On-Device Quantization-Aware Training for LLMs at Inference Cost. In Findings of the Association for Computational Linguistics: EMNLP 2026, pages 556–577, Budapest, Hungary. Association for Computational Linguistics.
Cite (Informal):
End-to-End On-Device Quantization-Aware Training for LLMs at Inference Cost (Tan et al., Findings 2026)
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PDF:
https://aclanthology.org/2026.findings-emnlp.28.pdf