Claude Fable 5.1
Anthropic馃嚭馃嚫
anthropic/claude-fable-5.1Claude Fable 5.1 is Anthropic's most capable model, released September 2026 as an upgrade to Claude Fable 5 for coding, knowledge work, and long-running problem-solving, with a 1M-token context window. It improves agentic coding by over 30% and doubles its predecessor's Terminal-Bench-Science score while cutting costs through cheaper cache reads, and is the openly available counterpart to the more tightly safeguarded Mythos 5.1.
Cost rate
10x
Context
1M
Released
Sep 1, 2026
Input
TextImageFile
Output
Text
Support
ReasoningTool callingStructured outputs
Best at
The categories where this model ranks highest.
Software & IT Services
#1 路 top 1%
Writing, Literature, & Language
#2 路 top 1%
Entertainment, Sports, & Media
#3 路 top 1%
Life, Physical, & Social Science
#5 路 top 1%
Performance
Median latency and throughput measured across recent requests.
Throughput57 tok/s
Latency