Claude Fable 5 tops the Artificial Analysis Intelligence Index with 64.9 points and sets records in five of ten benchmarks. But the gain over Opus 4.8 is just 5.7 percent at double the token price. Safety filters with fallback routing push costs even higher.

Anthropic is pricing both Fable 5 and Mythos 5 at $10 per million input tokens and $50 per million output tokens. The company says that is less than half the price of Claude…

Positioned a tier above the previous Opus models, Claude Fable 5 sets a new benchmark for generally available AI, outperforming rivals like OpenAI's GPT-5.5.