ModelRefs / GPTQ — AI Glossary
GPTQ — AI Glossary
A one-shot post-training quantization method for LLMs achieving near-lossless INT4 compression using second-order weight updates.
Overview
GPTQ (Frantar et al. 2022) quantizes LLMs to INT4 with <1% perplexity increase by using Hessian-based layer-wise reconstruction. It processes one layer at a time, compensating for quantization error. GPTQ models on HuggingFace are widely used for 4-bit inference on consumer GPUs via AutoGPTQ and ExLlamaV2.
Reference details
| Topic | training |
|---|---|
| Last reviewed | 2026-06-24 |
Related terms
Commonly confused with
GPTQ and AWQ both produce near-lossless 4-bit weights after training, and differ in how they decide what to protect. GPTQ reconstructs layer outputs using second-order information about the weights; AWQ identifies the small fraction of weights the activations actually depend on and keeps those at higher precision. Neither is a format — GGUF is a container, and either method's output can end up in one.
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Frequently asked questions
What is GPTQ?
A one-shot post-training quantization method for LLMs achieving near-lossless INT4 compression using second-order weight updates.
What concepts are related to GPTQ?
Closely related concepts include awq, quantization, gguf.