Reasoning benchmark
Epoch Capabilities Index leaderboard
As of October 2026, Claude Opus 5.5 has the highest published Epoch Capabilities Index score on Noometry at 167.33, out of 213 models with results.
Last verified
About Epoch Capabilities Index
Epoch AI's composite capability score, fitted across many benchmarks with item response theory.
Top 15 models
- Claude Opus 5.5 167.33
- GPT-6 Astra 166.45
- GPT-6.1 Sol 166.09
- Claude Sonnet 5.5 165.03
- Claude Fable 5.1 164.7
- Claude Opus 5 162.78
- GPT-6 Sol 162.72
- GPT-5.5 Pro 162.07
- Claude Fable 5 162.06
- GPT-5.6 Sol 161.66
- GPT-5.6 Terra 159.62
- GPT-5.5 159.1
- GPT-5.4 Pro 158.93
- Claude Opus 4.8 158.21
- Kimi K3 157.45
Sponsored placements are available on pages like this one. Advertise on Noometry
All results
Compare the leaders
Frequently asked questions
What does Epoch Capabilities Index measure?
Epoch AI's composite capability score, fitted across many benchmarks with item response theory.
Which model has the highest Epoch Capabilities Index score?
As of October 2026, Claude Opus 5.5 has the highest published Epoch Capabilities Index score on Noometry at 167.33, out of 213 models with results.
What is the best open-weight model on Epoch Capabilities Index?
Kimi K3 has the highest Epoch Capabilities Index score among open-weight models at 157.45, ranking 15 of 213 overall.