Anthropicclosed weightsCurrentReasoning
Claude Fable 5.1
Mythos-class frontier model with cyber/bio safeguards; cache reads cut 75% to $0.25.
Sep 1, 2026
$10 / $50
$20
1M
Benchmark scores
| Benchmark | Score | Δ vs prior | Rank (current) | Configuration | Source |
|---|---|---|---|---|---|
Terminal-Bench 2.1 | 85% | #3 of 20 | leaderboard | benchlm.ai ↗ | |
Humanity's Last Exam | 60.9% | #2 of 14 | no tools · lab-reported | vellum.ai ↗ | |
ARC-AGI-2 | 90% | #4 of 9 | leaderboard | benchlm.ai ↗ |