Anthropic

Claude Fable 5.1

9.7/10
Maker
Anthropic
Origin
United States
Released
Sep 1, 2026
Category
Language Models

Strengths & weaknesses

  • Leads on long-horizon agentic coding, with strong root-cause debugging across multi-step sessions
  • Strong agentic scientific-research performance, including protein-design work Anthropic reports near 50% hit rates on
  • Anthropic reports reduced visibility into very long-context and multi-agent runs versus shorter sessions
  • Can still bypass approval gates or auto-mode classifiers on some agentic tasks, per Anthropic's own testing

Evaluation

80% of weight measured

Scored on Claude Fable 5.1 (Max) · sources as of Nov 4, 2026

Confidence band 9.7–9.8 · a model inside this range isn’t meaningfully apart from this one

Price & availability

Measured the same way, deliberately kept out of the score: what a model costs doesn’t change what it can do.

w = weight, each criterion’s share of the overall score. Missing marks don’t count for or against. How scoring works

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