tatsu-lab/alpaca_eval
An automatic evaluator for instruction-following language models developed at Stanford, using length-controlled win rates correlated 0.98 with ChatBot Arena.

AlpacaEval is an automated benchmarking system for evaluating chat LLMs. It uses GPT-4 as an annotator to compare model outputs against a baseline and computes win rates to rank models. The system implements length-controlled win rates to prevent length gaming and achieves 0.98 Spearman correlation with ChatBot Arena while costing under $10 and completing in under 5 minutes. It serves as a fast, cheap alternative to human preference evaluation for LLM leaderboards.
Frequently asked
- What is tatsu-lab/alpaca_eval?
- An automatic evaluator for instruction-following language models developed at Stanford, using length-controlled win rates correlated 0.98 with ChatBot Arena.
- Is alpaca_eval open source?
- Yes — tatsu-lab/alpaca_eval is open source, released under the Apache-2.0 license.
- What language is alpaca_eval written in?
- tatsu-lab/alpaca_eval is primarily written in Jupyter Notebook.
- How popular is alpaca_eval?
- tatsu-lab/alpaca_eval has 2k stars on GitHub.
- Where can I find alpaca_eval?
- tatsu-lab/alpaca_eval is on GitHub at https://github.com/tatsu-lab/alpaca_eval.