GPT Image 2.5 Dev vs Claude Fable 5.1

OpenAI GPT Image 2.5 DevAnthropic Claude Claude Fable 5.1
VendorOpenAIAnthropic Claude
Context window—1,000,000
Max output—128,000
ReasoningNoYes
Tool callingNoYes
File inputYesYes
Inputtext, imagetext, image, file
Outputimagetext
Released2026-09-082026-09-01