grok-4-fast-non-reasoning vs GPT Image 2 Develop

xAI grok-4-fast-non-reasoningOpenAI GPT Image 2 Develop
VendorxAIOpenAI
Context window2,097,152128,000
Max output30,000
ReasoningNoNo
Tool callingYesNo
File inputYesYes
Inputtext, imagetext, image
Outputtextimage
Released2025-08-272026-04-19