The Slop Index: Which AI Model Writes the Least Like AI?

The Slop Index is a live benchmark scoring 39 frontier models (the board lists 58 models across 112 scenarios and 64,636 generations) on how much their writing resembles AI slop, with higher scores meaning more chatbot-like. Scores blend a blind human arena vote (40%) with conciseness, templating, rhythm and tells (15% each), measured against genuine human writing collected before ChatGPT existed, including workplace email from 2000–2002 and pre-2022 tweets. No LLM judges anything; the arena lets anyone vote on two blind samples from the same task.