gpt-5-nano vs Grok 4.20

OpenAI gpt-5-nanoxAI Grok 4.20
VendorOpenAIxAI
Context window400,0002,000,000
Max output128,0002,000,000
ReasoningYesYes
Tool callingYesYes
File inputYesYes
Inputtext, imagetext, image
Outputtexttext
Released2025-08-072026-03-08