Claude Opus 5.5
168.67ECI · Rank 4 · 165.78–171.91
Model release: 2026-09-22
Access: API access
Observed history
| Snapshot | Rank | ECI | Method |
|---|---|---|---|
| 2026-11-02T03:49 UTC | 2 | 168.40 | Legacy ECI |
| 2026-11-07T08:13 UTC | 3 | 168.36 | Bayesian ECI |
| 2026-11-09T22:32 UTC | 4 | 168.67 | Bayesian ECI |