Grok Build 0.1 vs gpt-5-mini

xAI Grok Build 0.1OpenAI gpt-5-mini
VendorxAIOpenAI
Context window256,000400,000
Max output—128,000
ReasoningYesYes
Tool callingYesYes
File inputYesYes
Inputtext, imagetext, image
Outputtexttext
Released2026-05-302025-08-07