Anthropic · Claude Fable line · flagship
Claude Fable 5.1 was released by Anthropic on September 1, 2026, as a flagship model in the Claude Fable line.
Anthropic's top model, refreshed: big jumps on long coding and scientific-research tasks, and cached input now costs 75% less — same headline price as Fable 5.
Compared with Claude Fable 5 · the model it replaces
Finishes over half of long multi-step coding tasks
Terminal-Bench 4.0 — long agentic coding sessions in a terminal
55.8%
▲ up from 42.0% · +14 points
Doubles its score on agentic scientific research
Terminal-Bench-Science 0.1 — running real research workflows end to end
52.6%
▲ up from 24.7% · more than doubled
Same price — and cached input now costs 75% less
Price per 1M tokens — what developers pay, input / output
$10 / $50
same as Fable 5 · cache reads now $0.25
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Claude Fable 5.1 is the current model in this line. The card shows how long it has been since the last release against the line's usual gap and its recent ones — the rhythm, not a date.
Latest: Claude Fable 5.1 · Sep 1, 2026
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