GPT-5.4 Mini vs grok-4-fast-reasoning

OpenAI GPT-5.4 MinixAI grok-4-fast-reasoning
VendorOpenAIxAI
Context window400,0002,097,152
Max output128,00030,000
ReasoningYesYes
Tool callingYesYes
File inputYesYes
Inputtext, imagetext, image
Outputtexttext
Released2026-03-172025-08-27