Anthropic ECI (AECI) — leaderboard
Anthropic's internal fork of the Epoch Capabilities Index, using IRT over public and internal benchmark results to track Claude capability progression.
Metric: AECI Score. Source: abstatisticalconsulting.substack.com. Status: saturation imminent. 10 models tracked.
Top models
| # | Model | Score |
|---|---|---|
| 1 | Claude Mythos Preview | 159.2 |
| 2 | Claude Opus 4.7 | 155.1 |
| 3 | Claude Opus 4.6 | 152.1 |
| 4 | Claude Opus 4.5 | 149 |
| 5 | Claude Sonnet 4.5 | 145.3 |
| 6 | Claude Opus 4 | 141.6 |
| 7 | Claude 3.7 Sonnet | 139.2 |
| 8 | Claude 3.5 Sonnet | 132.7 |
| 9 | Claude 3 Opus | 125.7 |
Interactive version: theaggregate.ai/benchmark?slug=anthropic-eci-aeci · How the rankings work · Data refreshed daily, snapshot 2026-07-22.