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Claude Fable 5.1 made me a really nice animated pelican

AnnouncementModelSep 1, 2026

Anthropic says Claude Fable 5.1 scored 52.6% on the new Terminal-Bench-Science 0.1 benchmark, up from 24.7% for Fable 5 and 22.4% for GPT-5.6. The author tested Fable 5.1's five reasoning levels by generating SVG pelicans: low and medium skipped visible reasoning, while max produced the best result at 65,927 output tokens, 13 minutes 54 seconds, and $3.30. An animated version was created by piping the max output back at high effort.

Receipt № 16881 source · awaiting confirmation ◐

Evidence

1source· awaiting independent confirmation

No score is assigned. Sources and their independence are shown in the citation chain below.

Citation chain · 1 source

AnthropicCompanyFable 5ModelGPT-5.6ModelOpus 5ModelClaude Fable 5.1ModelMythos 5.1Model
Canonical: https://simonwillison.net/2026/Sep/1/claude-fable-5-1/