Epoch Capabilities Index (ECI)
Composite that puts many benchmarks on one scale; the hub tracks 89 benchmarks
composite indexactive
Score, Epoch AI Benchmarking Hub
Definition
- Version
- not in the notes
- Category
- composite index
- Maintainer
- Epoch AI
- Status
- active
- Home page
- https://epoch.ai/benchmarks
Sources
- AI benchmarks & capabilities epoch.ai https://epoch.ai/benchmarks
- Claude Sonnet 5.5 erreicht Gleichstand mit Fable 5.1 im Epoch Index orcarouter.ai https://www.orcarouter.ai/de/blog/claude-sonnet-5-5-epoch-capabilities-index
Scores at a Glance
Score, Epoch AI Benchmarking Hub
Higher is better for this unit.
1
Claude Opus 5.5Anthropic
GPT-6 AstraOpenAIEpoch data file of 15 Oct 2026: 0.41 behind Claude Opus 5.5, within each other's confidence intervals
Claude Opus 5.5Anthropic166.82 index
maintainer-run2GPT-6 AstraOpenAIEpoch data file of 15 Oct 2026: 0.41 behind Claude Opus 5.5, within each other's confidence intervals166.41 index
maintainer-run050100150200
Where this comes from
Each bar is one model, with its most independent recorded score. Hatched bars are vendor-reported; the word beside each bar says who ran it. Settings and dates differ between rows; the Scores table below has every result.
Scores
| Model | Score | Who ran it | Setting | View or population | Date | Source |
|---|---|---|---|---|---|---|
| Claude Opus 5.5 | 166.82 index CI 163.54 to 170.99 | maintainer-run | – | rank 1, Epoch AI Benchmarking Hub | 15 Oct 2026 | epoch.ai |
| GPT-6 Astra | 166.41 index CI 163.35 to 171.23 | maintainer-run | Epoch data file of 15 Oct 2026: 0.41 behind Claude Opus 5.5, within each other's confidence intervals | rank 2, Epoch AI Benchmarking Hub | 15 Oct 2026 | epoch.ai |
Where this comes from
Scores from different settings, harnesses or dates are not directly comparable; the row says which. Sorted by score, highest first, as a reading aid, not a ranking.
To cite this page: Project AURION, AI Use-Cases Research & Innovation, "Epoch Capabilities Index (ECI)", https://aurion.semai.id/benchmarks/epoch-capabilities-index/, records of October 2026.