GPT-5.4 Nano vs Claude Opus 5.5

OpenAI GPT-5.4 NanoAnthropic Claude Claude Opus 5.5
VendorOpenAIAnthropic Claude
Context window400,0001,000,000
Max output128,000128,000
ReasoningYesYes
Tool callingYesYes
File inputYesYes
Inputtext, imagetext, image, file
Outputtexttext
Released2026-03-172026-09-22