Fable 5.1 release: Doubles scientific agent scores, cuts costs by 25%
mark_k · x · 2026-09-02
Anthropic released Fable 5.1, a major upgrade despite the minor version bump. It scores 52.6% on Terminal-Bench-Science (up from 24.7% for Fable 5) and shows significant gains on Terminal-Bench 4.0, CursorBench, and AutomationBench. It outperforms predecessors in coding, knowledge work, computer use, and reasoning. Costs are 25% lower for typical workloads and up to 45% lower for agentic workloads.
Related event: Fable 5.1 Doubles Science Agent Benchmark Scores(4 posts)→
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