Claude Sonnet 5.5 vs grok-4-fast-non-reasoning

Anthropic Claude Claude Sonnet 5.5xAI grok-4-fast-non-reasoning
VendorAnthropic ClaudexAI
Context window1,000,0002,097,152
Max output128,00030,000
ReasoningYesNo
Tool callingYesYes
File inputYesYes
Inputtext, image, filetext, image
Outputtexttext
Released2026-09-282025-08-27