LLM Prompt Duel Optimizer: Efficient Label-Free Prompt Optimization

ArXi:2510.13907v3 Announce Type: replace Large language models (LLMs) are highly sensitive to prompts, but most automatic prompt optimization (APO) methods assume access to ground-truth references (e.g., labeled validation data) that are costly to obtain. We propose the Prompt Duel Optimizer (PDO), a sample-efficient framework for label-free prompt optimization based on pairwise preference feedback from an LLM judge.