---
title: 'Humanity''s Last Exam'
license: CC-BY-4.0
license_url: https://creativecommons.org/licenses/by/4.0/
license_note: 'paper is CC BY 4.0 (verified on arXiv abs page 2026-11-11; icon by-4.0.png, http://creativecommons.org/licenses/by/4.0/); note is our own summary'
source: https://iinventedlight.com/library/notes/2501-14249-humanitys-last-exam.md
source_license: 'CC BY 4.0'
attribution: 'Summary by iinventedlight (AI-assisted). Source: Long Phan, Alice Gatti, Ziwen Han, Nathaniel Li, Josephina Hu, Hugh Zhang, et al. (1181 authors), Humanity''s Last Exam (CC BY 4.0).'
author: 'iinventedlight (AI-assisted)'
date: 2026-11-11
status: published
approved_by: "Cole Withington, 2026-11-11 20:58 PT, Grok Bot chat widget t1717s7407: \"Publish all 100 including the LLMs Encode Clinical Knowledge note\""
checked_on: 2026-11-11
as_of: 2026-11-11
confidence: medium
untested: 'Not reproduced. Abs page and HTML key sections read 2026-11-11. Named code URLs checked; code not run.'
category: arxiv
topic_area: 'ai-research: evals'
tags: arxiv, evals, benchmarks
arxiv_id: 2501.14249
alias: 2501.14249-humanitys-last-exam
sources:
  - id: S1
    title: 'Humanity''s Last Exam'
    publisher: arXiv
    authors: 'Long Phan, Alice Gatti, Ziwen Han, Nathaniel Li, Josephina Hu, Hugh Zhang, et al. (1181 authors)'
    url: https://arxiv.org/abs/2501.14249
    version_read: 'v12 (19 Oct 2026)'
    accessed: 2026-11-11
    license: 'CC BY 4.0'
---
# Humanity's Last Exam

## Summary
Humanity's Last Exam (HLE) is a multi-modal benchmark of 2,500 expert-written questions across dozens of subjects, including mathematics, humanities, and the natural sciences. The authors designed it as a difficult closed-ended academic benchmark, with questions that have known, verifiable answers but cannot be quickly solved by internet retrieval. They note that LLMs now achieve over 90% accuracy on popular benchmarks like MMLU, and that state-of-the-art LLMs demonstrate low accuracy and calibration on HLE. The public release is at lastexam.ai. This note uses the v12 text last revised 19 Oct 2026. [S1]

## Claims
- id: C1
  claim: 'HLE consists of 2,500 questions across dozens of subjects.'
  source: S1
  evidence: "HLE consists of 2,500 questions across dozens of subjects"
- id: C2
  claim: 'The authors say models now achieve over 90% accuracy on popular benchmarks like MMLU.'
  source: S1
  evidence: "LLMs now achieve over 90% accuracy on popular benchmarks like MMLU"
- id: C3
  claim: 'They publicly release HLE at lastexam.ai.'
  source: S1
  evidence: "we publicly release HLE at https://lastexam.ai"

## Verification
- Code available: The public release is https://lastexam.ai, which returned HTTP 200 on 2026-11-11. No official GitHub URL was named as the primary release. Not run.
- Reproduced: not reproduced (2026-11-11). Code not run.
- Related work: Live note 2601-04301-test-set-contamination-generative-evals. This is the paper-verification note for Humanity's Last Exam itself.
- Limits: This note follows the v12 abstract and key sections (last revised 19 Oct 2026) and does not restate model-by-model scores, which can change across revisions. High accuracy on HLE is described by the authors as evidence on closed-ended academic questions, not as a complete measure of research ability.
- License: CC BY 4.0 on the abs page (2026-11-11; icon by-4.0.png; http://creativecommons.org/licenses/by/4.0/). Submitted 24 Jan 2025 (v1); last revised 19 Oct 2026 (v12). Sources: [S1] https://arxiv.org/abs/2501.14249, v12 (19 Oct 2026). checked_on: 2026-11-11.

## When to apply
Use when you need a current, expert-written hard academic benchmark and its official public page, not a stale score table.

## Facts
- id: F1
  claim: 'HLE is a multi-modal benchmark of 2,500 questions across dozens of subjects.'
  confidence: medium
  date: 2026-11-11
  sources: [S1]
  license: CC BY 4.0
- id: F2
  claim: 'The authors report that models already exceed 90% accuracy on popular benchmarks such as MMLU.'
  confidence: medium
  date: 2026-11-11
  sources: [S1]
  license: CC BY 4.0
- id: F3
  claim: 'They publicly release HLE at https://lastexam.ai.'
  confidence: medium
  date: 2026-11-11
  sources: [S1]
  license: CC BY 4.0

## Sources
- [S1] arXiv 2501.14249, https://arxiv.org/abs/2501.14249. License: CC BY 4.0. v12 (19 Oct 2026). Accessed 2026-11-11.

License: this note is CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). Summary by iinventedlight (AI-assisted). Paper is CC BY 4.0.

---

Agents: [/agents.md](/agents.md) | [/.well-known/agent-library.json](/.well-known/agent-library.json).