METR Time Horizon 1.1
Agents attempt 228 software and research tasks timed against skilled humans, run in Inspect. The score is the human task length at which the agent succeeds half the time.
It added 73 HCAST tasks, removed 15 and updated 53, and moved from Vivaria to Inspect. METR stopped updating the page on 2026-09-08 and calls results above 16 hours unreliable.
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.
- Level
- Research frontier Researchers, on open problems or tasks that take days
- Scored
- Checked automatically A program checks the result against an answer key, unit tests or the expected final state.
- Answers
- Agent task Many steps in a terminal, browser, desktop, app, game or robot.
Claude Mythos Preview leads with 17.4 h among models released by Apr 2026
Best score per model from the benchmark's own leaderboard, read on 2 Nov 2026. Where a model ran with several settings or harnesses, we keep its best.
The newest model with a score here came out in Apr 2026, and nobody has tested a newer one. Among the 20 highest-ranked models on the capability index, these have no score yet:
- GPT-6 Astra
- Claude Opus 5.5
- GPT-6.1 Terra
- GPT-6.1 Sol
- and 16 more
- 17.4 h Claude Mythos Preview
- 12.0 h Claude Opus 4.6
- 6.4 h
Gemini 3.1 Pro
- 5.9 h GPT-5.2
- 5.8 h GPT-5.3 Codex
- 5.7 h GPT-5.4
- 4.9 h Claude Opus 4.5
- 3.7 h
Gemini 3 Pro
- 3.7 h GPT-5.1-Codex-Max
- 3.4 h GPT-5
- 120 min o3
- 100 min Claude Opus 4.1
- 100 min Claude Opus 4
- 60 min Claude 3.7 Sonnet
- 39 min o1
- 21 min Claude 3.5 Sonnet (October 2024)
- 20 min o1-preview
- 11 min Claude 3.5 Sonnet
- 7.0 min GPT-4o
- 4.0 min GPT-4 Turbo
- 4.0 min GPT-4
- 4.0 min Claude 3 Opus
- 3.7 min GPT-4 Turbo
- 0.6 min GPT-3.5 Turbo Instruct
- 0.1 min davinci-002
- 0.1 min GPT-2 (1.5B)
- 1 Claude Mythos Preview 17.4 h
- 2 Claude Opus 4.6 12.0 h
- 3
Gemini 3.1 Pro 6.4 h
- 4 GPT-5.2 high 5.9 h
- 5 GPT-5.3 Codex high 5.8 h
- 6 GPT-5.4 xhigh 5.7 h
- 7 Claude Opus 4.5 4.9 h
- 8
Gemini 3 Pro 3.7 h
- 9 GPT-5.1-Codex-Max 3.7 h
- 10 GPT-5 3.4 h
- 11 o3 120 min
- 12 Claude Opus 4.1 100 min
- 13 Claude Opus 4 100 min
- 14 Claude 3.7 Sonnet 60 min
- 15 o1 39 min
- 16 Claude 3.5 Sonnet (October 2024) 21 min
- 17 o1-preview 20 min
- 18 Claude 3.5 Sonnet 11 min
- 19 GPT-4o May 2024 7.0 min
- 20 GPT-4 Turbo Nov 2023 4.0 min
- 21 GPT-4 Mar 2023 4.0 min
- 22 Claude 3 Opus 4.0 min
- 23 GPT-4 Turbo Apr 2024 3.7 min
- 24 GPT-3.5 Turbo Instruct 0.6 min
- 25 davinci-002 0.1 min
- 26 GPT-2 (1.5B) 0.1 min
| # | Model | Score | Setting | Date | Source |
|---|---|---|---|---|---|
| 1 | Claude Mythos Preview | 17.4 h | metr_agents/react | Apr 2026 | Official leaderboard |
| 2 | Claude Opus 4.6 | 12.0 h | metr_agents/react | Feb 2026 | Official leaderboard |
| 3 | | 6.4 h | triframe_inspect/triframe_agent | Feb 2026 | Official leaderboard |
| 4 | GPT-5.2 | 5.9 h | high, triframe_inspect/triframe_agent | Dec 2025 | Official leaderboard |
| 5 | GPT-5.3 Codex | 5.8 h | high, triframe_inspect/triframe_agent | Feb 2026 | Official leaderboard |
| 6 | GPT-5.4 | 5.7 h | xhigh, metr_agents/react | Mar 2026 | Official leaderboard |
| 7 | Claude Opus 4.5 | 4.9 h | metr_agents/react | Nov 2025 | Official leaderboard |
| 8 | | 3.7 h | metr_agents/react | Nov 2025 | Official leaderboard |
| 9 | GPT-5.1-Codex-Max | 3.7 h | triframe_inspect/triframe_agent | Nov 2025 | Official leaderboard |
| 10 | GPT-5 | 3.4 h | triframe_inspect/triframe_agent | Aug 2025 | Official leaderboard |
| 11 | o3 | 120 min | triframe_inspect/triframe_agent | Apr 2025 | Official leaderboard |
| 12 | Claude Opus 4.1 | 100 min | metr_agents/react | Aug 2025 | Official leaderboard |
| 13 | Claude Opus 4 | 100 min | metr_agents/react | May 2025 | Official leaderboard |
| 14 | Claude 3.7 Sonnet | 60 min | metr_agents/react | Feb 2025 | Official leaderboard |
| 15 | o1 | 39 min | triframe_inspect/triframe_agent | Dec 2024 | Official leaderboard |
| 16 | Claude 3.5 Sonnet (October 2024) | 21 min | metr_agents/react | Oct 2024 | Official leaderboard |
| 17 | o1-preview | 20 min | Sep 2024 | Official leaderboard | |
| 18 | Claude 3.5 Sonnet | 11 min | metr_agents/react | Jun 2024 | Official leaderboard |
| 19 | GPT-4o May 2024 | 7.0 min | metr_agents/react | May 2024 | Official leaderboard |
| 20 | GPT-4 Turbo Nov 2023 | 4.0 min | metr_agents/react | Nov 2023 | Official leaderboard |
| 21 | GPT-4 Mar 2023 | 4.0 min | Mar 2023 | Official leaderboard | |
| 22 | Claude 3 Opus | 4.0 min | metr_agents/react | Feb 2024 | Official leaderboard |
| 23 | GPT-4 Turbo Apr 2024 | 3.7 min | metr_agents/react | Apr 2024 | Official leaderboard |
| 24 | GPT-3.5 Turbo Instruct | 0.6 min | Sep 2023 | Official leaderboard | |
| 25 | davinci-002 | 0.1 min | Mar 2022 | Official leaderboard | |
| 26 | GPT-2 (1.5B) | 0.1 min | Nov 2019 | Official leaderboard |
3 models have held number one since its release in Jan 2026
Lab claims count from the day the card came out, independent runs from the model’s release.
Scores over time
All the scores we have, one dot each, so a model tested at several settings appears more than once.
No lab model card reports it yet
We read the headline results of 479 launch posts from 51 labs, and none of them list this benchmark.
Versions
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