Grok 4.7 vs GPT-5.6 Luna

xAI Grok 4.7OpenAI GPT-5.6 Luna
VendorxAIOpenAI
Context window500,0001,050,000
Max output—128,000
ReasoningYesYes
Tool callingYesYes
File inputYesYes
Inputtext, imagetext, image
Outputtexttext
Released2026-09-212026-07-09