  Large language models (LLMs) strengthen instruction-following capability
through instruction-finetuning (IFT) on supervised instruction/response data.
However, widely used IFT datasets (e.g., Alpaca's 52k data) surprisingly
contain many low-quality instances with incorrect or irrelevant responses,
which are misleading and detrimental to IFT. In this paper, we propose a simple
and effective data selection strategy that automatically identifies and filters
out low-quality data using a strong LLM (e.g., ChatGPT). To this end, we
introduce AlpaGasus, which is finetuned on only 9k high-quality data filtered
from the 52k Alpaca data. AlpaGasus significantly outperforms the original
Alpaca as evaluated by GPT-4 on multiple test sets and the controlled human
evaluation. Its 13B variant matches $>90\%$ performance of its teacher LLM
(i.e., Text-Davinci-003 generating the 52k data) on test tasks. It also
provides 5.7x faster training, reducing the training time for a 7B variant from
80 minutes (for Alpaca) to 14 minutes. Moreover, the experiments prove the
efficacy of our method across diverse datasets, base models, and LLM filters.
Overall, AlpaGasus demonstrates a novel data-centric IFT paradigm that can be
generally applied to instruction-tuning data, leading to faster training and
better instruction-following models. Our project page is available at:
https://lichang-chen.github.io/AlpaGasus/
