Anthropicclosed weightsCurrentReasoning
Claude Sonnet 5.5
Adaptive thinking; cache reads cut to $0.10 in Oct 2026.
Sep 28, 2026
$2 / $10
$4
1M
Benchmark scores
| Benchmark | Score | Δ vs prior | Rank (current) | Configuration | Source |
|---|---|---|---|---|---|
Terminal-Bench 2.1 | 83.1% | #4 of 20 | leaderboard | benchlm.ai ↗ | |
Humanity's Last Exam | 56.9% | #4 of 14 | no tools · lab-reported | anthropic.com ↗ |