Grok Build 0.1 vs Claude Sonnet 5.5

xAI Grok Build 0.1Anthropic Claude Claude Sonnet 5.5
VendorxAIAnthropic Claude
Context window256,0001,000,000
Max output—128,000
ReasoningYesYes
Tool callingYesYes
File inputYesYes
Inputtext, imagetext, image, file
Outputtexttext
Released2026-05-302026-09-28