Models · Claude
Claude Opus 5.5
Asked for a few hundred random integers, Claude Opus 5.5 does not pick evenly. This page is the shape of that preference, built from 36 recorded answers containing 10621 numbers, and it is what the identify tool compares a pasted reply against.
- Bank id
claude-opus-5-5- Family
- Claude
- Collected through
- API
- Collected on
- 2026-09-23
- Status
- Inherited from ModelTrace; serving identity not independently verified
- Distinct values used
- 355 of 355
- Prompt environments
- 12 of 12
Capability and price
- Sold by
- Anthropic
- Intelligence index
- 58 · v4.3.2, scored as adaptive reasoning, max effort, default fallback
- Index rank
- 1 of 11
- Input, per 1M tokens
- 4.00
- Output, per 1M tokens
- 20.00
- Blended, per 1M tokens
- 8.00
- Price rank
- 9 of 11
- Context window
- 1,000,000 tokens
Read on 2026-09-23, not measured here: index page · price page
Distribution
Every bar is one value from 1 to 355; its height is how many times the model chose it across all recorded answers. A perfectly random picker would give a flat line. Nothing in the bank does.
Favourite numbers
| Number | Times chosen | Share |
|---|---|---|
| 57 | 39 | 0.37% |
| 12 | 38 | 0.36% |
| 99 | 38 | 0.36% |
| 199 | 38 | 0.36% |
| 7 | 37 | 0.35% |
| 9 | 37 | 0.35% |
| 17 | 37 | 0.35% |
| 19 | 37 | 0.35% |
| 67 | 37 | 0.35% |
| 85 | 37 | 0.35% |
| 87 | 37 | 0.35% |
| 97 | 37 | 0.35% |
How reliably it is recognised
In held-out testing across all twelve prompt environments, 12 of 12 three-answer runs named this model with a clear margin, 0 were close calls inside its family, 0 had only a weak match, and 0 named a different model with a clear margin.
With this model removed from the bank and its own answers scored against the rest, 0 of 12 runs still named another model with a clear margin, 0 were close calls inside the family, and 12 had only a weak match. Its answers landed most often on GPT-5.4 (11 of 12). That is the number to keep in mind if you are testing a version that is not listed here.
Taken as published from upstream ModelTrace 55a2e4a, with no replies or holdout of our own. Cross-validated on upstream's 36 replies (not a holdout), single-reply top-1 is 33/36 for GPT-6 Sol and 36/36 for GPT-6 Luna and Claude Opus 5.5; all three reach 12/12 at three replies. Added in v2026.09.5 by an Owner decision although admission rule 3 moved from 131 to 132 on 1,512 removed-model cases; the changelog lists every change.
Both measurements count the status the site attaches to the first-ranked model, not the bare ranking alone. The methodology page explains how they were made and what they leave out.