Benchmark Almanac

METR Time Horizon

Claude Opus 4.5 4.1 h leads since November 2025
Claude Mythos Preview 17.4 h leads since April 2026
Only in system cards

Agents attempt software and research tasks timed against skilled humans. The score is the human task length at which the agent succeeds half the time.

Time Horizon 1.0 used 170 tasks in Vivaria. METR replaced it with Time Horizon 1.1 in January 2026 and re-estimated 14 models.

Made by
METR
Released
March 2025
Kind
Task length
Level
Research frontier
Scored
Checked automatically
Answers
Agent task
Strongest model tested
Claude Opus 4.5 #61 on the capability index
Last in a system card
July 2026
Last model added
July 2026
Scores refreshed
November 12th, 2026

In the authors’ words

Despite rapid progress on AI benchmarks, the real-world meaning of benchmark performance remains unclear. To quantify the capabilities of AI systems in terms of human capabilities, we propose a new metric: 50%-task-completion time horizon. This is the time humans typically take to complete tasks that AI models can complete with 50% success rate. We first timed humans with relevant domain expertise on a combination of RE-Bench, HCAST, and 66 novel shorter tasks. On these tasks, current frontier AI models such as Claude 3.7 Sonnet have a 50% time horizon of around 50 minutes. Furthermore, frontier AI time horizon has been doubling approximately every seven months since 2019, though the trend may have accelerated in 2024. The increase in AI models' time horizons seems to be primarily driven by greater reliability and ability to adapt to mistakes, combined with better logical reasoning and tool use capabilities. We discuss the limitations of our results – including their degree of external validity – and the implications of increased autonomy for dangerous capabilities. If these results generalize to real-world software tasks, extrapolation of this trend predicts that within 5 years, AI systems will be capable of automating many software tasks that currently take humans a month.

Abstract of Measuring AI Ability to Complete Long Software Tasks (arXiv:2503.14499, CC0)
31
Models scored on its own leaderboard
7
System cards report it, from 1 lab

Claude Opus 4.5 leads with 4.1 h among models released by November 2025

Best score per model from the benchmark's own leaderboard, read on November 12th, 2026. Where a model ran with several settings or harnesses, we keep its best.

Claude Mythos Preview leads with 17.4 h, claims included

Best score per model from every source, including labs’ own numbers and claims Epoch AI collected from reports and papers. Labs pick their own settings, so a claim can beat an independent run of the same model.

The newest model with a score here came out in November 2025, and nobody has tested a newer one. Among the 20 highest-ranked models on the capability index, these have no score yet:

  1. 1 Claude Opus 4.5 4.1 h
  2. 2 GPT-5.1-Codex-Max 2.7 h
  3. 3 GPT-5 2.2 h
  4. 4 Claude Sonnet 4.5 117 min
  5. 5 Claude Opus 4.1 109 min
  6. 6 Grok 4 105 min
  7. 7 o3 91 min
  8. 8 Claude Opus 4 84 min
  9. 9 Claude Sonnet 4 74 min
  10. 10 Kimi K2 Thinking 58 min
  11. 11 Claude 3.7 Sonnet 55 min
  12. 12 o1 42 min
  13. 13 Gemini 2.5 Pro Jun 2025 40 min
  14. 14 DeepSeek-R1 May 2025 33 min
  15. 15 Claude 3.5 Sonnet (October 2024) 30 min
  16. 16 DeepSeek-R1 28 min
  17. 17 DeepSeek-V3 Mar 2025 25 min
  18. 18 o1-preview 23 min
  19. 19 DeepSeek-V3 20 min
  20. 20 Claude 3.5 Sonnet 20 min
  21. 21 GPT-4o May 2024 10 min
  22. 22 GPT-4 Turbo Nov 2023 9.4 min
  23. 23 GPT-4 Turbo Apr 2024 7.8 min
  24. 24 Claude 3 Opus 7.1 min
  25. 25 GPT-4 Turbo (Jan 2024) 6.3 min
  26. 26 GPT-4 Mar 2023 6.0 min
  27. 27 Qwen2.5-72B 5.8 min
  28. 28 Qwen2-72B 2.5 min
  29. 29 GPT-3.5 Turbo Instruct 0.6 min
  30. 30 davinci-002 0.1 min
  31. 31 GPT-2 (1.5B) 0.1 min

Source: Official METR Time Horizon leaderboard

Sources: Another board, via Epoch AI (CC BY 4.0) and official METR Time Horizon leaderboard

#ModelScoreSettingDateSource
1 Claude Opus 4.5 4.1 h generate Nov 2025 Official leaderboard
2 GPT-5.1-Codex-Max 2.7 h generate Nov 2025 Official leaderboard
3 GPT-5 2.2 h Aug 2025 Official leaderboard
4 Claude Sonnet 4.5 117 min Sep 2025 Official leaderboard
5 Claude Opus 4.1 109 min Aug 2025 Official leaderboard
6 Grok 4 105 min Jul 2025 Official leaderboard
7 o3 91 min Apr 2025 Official leaderboard
8 Claude Opus 4 84 min May 2025 Official leaderboard
9 Claude Sonnet 4 74 min May 2025 Official leaderboard
10 Kimi K2 Thinking 58 min generate Nov 2025 Official leaderboard
11 Claude 3.7 Sonnet 55 min Feb 2025 Official leaderboard
12 o1 42 min Dec 2024 Official leaderboard
13 Gemini 2.5 Pro Jun 2025 40 min Jun 2025 Official leaderboard
14 DeepSeek-R1 May 2025 33 min May 2025 Official leaderboard
15 Claude 3.5 Sonnet (October 2024) 30 min Oct 2024 Official leaderboard
16 DeepSeek-R1 28 min Jan 2025 Official leaderboard
17 DeepSeek-V3 Mar 2025 25 min Mar 2025 Official leaderboard
18 o1-preview 23 min Sep 2024 Official leaderboard
19 DeepSeek-V3 20 min Dec 2024 Official leaderboard
20 Claude 3.5 Sonnet 20 min Jun 2024 Official leaderboard
21 GPT-4o May 2024 10 min May 2024 Official leaderboard
22 GPT-4 Turbo Nov 2023 9.4 min Nov 2023 Official leaderboard
23 GPT-4 Turbo Apr 2024 7.8 min Apr 2024 Official leaderboard
24 Claude 3 Opus 7.1 min Feb 2024 Official leaderboard
25 GPT-4 Turbo (Jan 2024) 6.3 min Jan 2024 Official leaderboard
26 GPT-4 Mar 2023 6.0 min Mar 2023 Official leaderboard
27 Qwen2.5-72B 5.8 min Sep 2024 Official leaderboard
28 Qwen2-72B 2.5 min Jun 2024 Official leaderboard
29 GPT-3.5 Turbo Instruct 0.6 min Sep 2023 Official leaderboard
30 davinci-002 0.1 min Mar 2022 Official leaderboard
31 GPT-2 (1.5B) 0.1 min Nov 2019 Official leaderboard
#ModelScoreSettingDateSource
1 Claude Mythos Preview 17.4 h Early Apr 2026 Claim in metr.org, via Epoch AI
2 Claude Opus 4.6 12.0 h unknown thinking Feb 2026 Collected by Epoch AI, source not named
3 Gemini 3.1 Pro 6.4 h Feb 2026 Claim in metr.org, via Epoch AI
4 GPT-5.2 5.9 h high Dec 2025 Collected by Epoch AI, source not named
5 GPT-5.3 Codex 5.8 h Feb 2026 Collected by Epoch AI, source not named
6 GPT-5.4 5.7 h xhigh Mar 2026 Claim in metr.org, via Epoch AI
7 Claude Opus 4.5 4.9 h no thinking Nov 2025 Collected by Epoch AI, source not named
8 Gemini 3 Pro 3.7 h Nov 2025 Collected by Epoch AI, source not named
9 GPT-5.1-Codex-Max 3.7 h Nov 2025 Claim in metr.org, via Epoch AI
10 GPT-5 3.4 h high Aug 2025 Collected by Epoch AI, source not named
11 o3 120 min unknown thinking Apr 2025 Collected by Epoch AI, source not named
12 Claude Sonnet 4.5 117 min Sep 2025 Official leaderboard
13 Claude Opus 4.1 109 min Aug 2025 Official leaderboard
14 Grok 4 105 min Jul 2025 Official leaderboard
15 Claude Opus 4 100 min May 2025 Collected by Epoch AI, source not named
16 Claude Sonnet 4 74 min May 2025 Official leaderboard
17 Claude 3.7 Sonnet 60 min Feb 2025 Collected by Epoch AI, source not named
18 Kimi K2 Thinking 58 min generate Nov 2025 Official leaderboard
19 o1 42 min Dec 2024 Official leaderboard
20 Gemini 2.5 Pro Jun 2025 40 min Jun 2025 Official leaderboard
21 DeepSeek-R1 May 2025 33 min May 2025 Official leaderboard
22 Claude 3.5 Sonnet (October 2024) 30 min Oct 2024 Official leaderboard
23 DeepSeek-R1 28 min Jan 2025 Official leaderboard
24 DeepSeek-V3 Mar 2025 25 min Mar 2025 Official leaderboard
25 o1-preview 23 min Sep 2024 Official leaderboard
26 DeepSeek-V3 20 min Dec 2024 Official leaderboard
27 Claude 3.5 Sonnet 20 min Jun 2024 Official leaderboard
28 GPT-4o May 2024 10 min May 2024 Official leaderboard
29 GPT-4 Turbo Nov 2023 9.4 min Nov 2023 Official leaderboard
30 GPT-4 Turbo Apr 2024 7.8 min Apr 2024 Official leaderboard
31 Claude 3 Opus 7.1 min Feb 2024 Official leaderboard
32 GPT-4 Turbo (Jan 2024) 6.3 min Jan 2024 Official leaderboard
33 GPT-4 Mar 2023 6.0 min Mar 2023 Official leaderboard
34 Qwen2.5-72B 5.8 min Sep 2024 Official leaderboard
35 Qwen2-72B 2.5 min Jun 2024 Official leaderboard
36 GPT-3.5 Turbo Instruct 0.6 min Sep 2023 Claim in metr.org, via Epoch AI
37 davinci-002 0.1 min Mar 2022 Official leaderboard
38 GPT-3 175B (davinci) 0.1 min May 2020 Claim in metr.org, via Epoch AI
39 GPT-2 (1.5B) 0.1 min Nov 2019 Official leaderboard

Epoch AI collected claims for 26 models from labs’ reports and papers. Switch the scores above to rank them together.

7 models have held number one on the official leaderboard since its release in March 2025 8 models have held number one with claims included since its release in March 2025

Lab claims count from the day the card came out, independent runs from the model’s release.

Anthropic OpenAI xAI
Own leaderboard Replaced by 1.1, Jan 2026

Source: Official METR Time Horizon leaderboard

Scores over time

All the scores we have, one dot each, so a model tested at several settings appears more than once.

On the benchmark’s own leaderboard A claim Epoch AI collected from a report or paper
0.0 min 0.1 min 1.0 min 10 min 100 min 16.7 h 166.7 h 2020 2021 2022 2023 2024 2025 2026 0.0 min 0.1 min 1.0 min 10 min 100 min 16.7 h 166.7 h 2020 2022 2024 2026

Sources: Official METR Time Horizon leaderboard and claims collected by Epoch AI (CC BY 4.0)

Labs report it only in system cards

We read the headline results of 522 launch posts from 52 labs, and none of them list this benchmark. Some system cards do, below.

7 system cards report it, from 1 lab

Besides launch posts, we read the system cards, model cards and technical reports labs publish with a release. They report far more, including safety and frontier-risk tests.

DateDocumentScoreAs the document writes itSection
Jul 9, 2026 GPT-5.6 Sol system card METR Time Horizon 1.1, METR did not treat the result as robust because of detected cheating, no number (9.1.3.6) AI R&D risk
Jun 25, 2026 GPT-5.6 Sol system card METR Time Horizon 1.1, METR did not treat the result as robust because of detected cheating, no number (9.1.3.6) AI R&D risk
Nov 18, 2025 GPT-5.1-Codex-Max system card 162 METR 50% time horizon, point estimate 2h42m, range 75 to 350 minutes (5.1.3.6) Autonomy
Aug 7, 2025 GPT-5 system card 135 METR 50%-time horizon of about 2h15m (95% CI 65m to 4h30m) (5.1.3.7) Autonomy
Apr 16, 2025 o4-mini system card 75 METR time horizon score, 50% reliability, about 1 hour 15 minutes (3.9.1) Autonomy
Apr 16, 2025 o3 system card 90 METR time horizon score, 50% reliability, about 1 hour 30 minutes (3.9.1) Autonomy
Feb 27, 2025 GPT-4.5 system card 30 METR time horizon score, 50% reliability, around 30 minutes (Figure 1 caption, 3.4) Autonomy

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