Grok 4.6 vs GPT Image 2.5 Dev

xAI Grok 4.6OpenAI GPT Image 2.5 Dev
VendorxAIOpenAI
Context window500,000—
Max output2,000,000—
ReasoningYesNo
Tool callingYesNo
File inputYesYes
Inputtext, imagetext, image
Outputtextimage
Released2026-08-132026-09-08