Claude Fable 5.1

claude-fable-5-1

For demanding reasoning and long-horizon agentic work

Intelligence: 53.4
Context: 1M
Training cutoff: 2026-06
Added: 2026-09-03
Inputs: Vision

Providers

One route serves Claude Fable 5.1, and every figure below is measured on it. Where the selected window has too little traffic, the figure names what it is based on instead.

Anthropic only route

claude-fable-5-1

Uptime

100.0%

Input / 1M: $10.00
Output / 1M: $50.00
TTFT: 1.65s fixed prompt · n=8
Output rate: 75.8 tok/s fixed prompt · n=8

1M context 128,000 max output cache $0.25 read / $20.00 write per 1M VisionRetention 30 days Training No Provider terms, reviewed 2026-10-13warming · 30m

Prompt caching Automatic reuse Not advertised Cache key Trailing breakpoint Caller breakpoints 1h, 5m

TTFT is the median time to the first visible answer token over real ModelRelay requests, with a fixed prompt standing in for models that have no traffic yet. Speed ranks by it. Intelligence is the Artificial Analysis Intelligence Index.