Claude Opus 5 first look: near Fable performance at one-third the cost

Anthropic released Claude Opus 5, which approaches or exceeds Fable/Mythos in benchmarks while costing about one-third. Suspected to be a distilled model, with cyber and biology capabilities deliberately subdued and guardrails loosened. Community evaluation ongoing.

• Anthropic
• Mythos
• 蒸馏
• Fable
• ベンチマーク
• Claude Opus 5