gpt-4o-image vs Claude Fable 5.1

OpenAI gpt-4o-imageAnthropic Claude Claude Fable 5.1
VendorOpenAIAnthropic Claude
Context window—1,000,000
Max output—128,000
ReasoningNoYes
Tool callingNoYes
File inputNoYes
Inputtexttext, image, file
Outputimage, texttext
Released—2026-09-01