Claude Fable 5.1 vs Grok 4.7

Anthropic Claude Claude Fable 5.1xAI Grok 4.7
VendorAnthropic ClaudexAI
Context window1,000,000500,000
Max output128,000—
ReasoningYesYes
Tool callingYesYes
File inputYesYes
Inputtext, image, filetext, image
Outputtexttext
Released2026-09-012026-09-21