GPT-5.5 vs Grok 4.20 Multi-Agent

OpenAI GPT-5.5xAI Grok 4.20 Multi-Agent
VendorOpenAIxAI
Context window1,050,0002,048,000
Max output128,0001,000,000
ReasoningYesYes
Tool callingYesYes
File inputYesYes
Inputtext, imagetext, image
Outputtexttext
Released2026-04-232026-03-08