HLE-Diamond: leaderboard

CAIS and Scale AI's refined 1,000-question subset of Humanity's Last Exam, after a year of cleaning: 500 reasoning and 500 expert-knowledge questions, answered closed-book without tools.

Source: lastexam.ai.

Interactive version: theaggregate.ai/benchmark?slug=hle-diamond · How It Works · Data refreshed daily, snapshot 2026-09-25.