GPT Image 2.5 Dev vs GPT-5.6 Luna

OpenAI GPT Image 2.5 DevOpenAI GPT-5.6 Luna
VendorOpenAIOpenAI
Context window—1,050,000
Max output—128,000
ReasoningNoYes
Tool callingNoYes
File inputYesYes
Inputtext, imagetext, image
Outputimagetext
Released2026-09-082026-07-09