o3 vs GPT-5

OpenAI o3OpenAI GPT-5
VendorOpenAIOpenAI
Context window200,000400,000
Max output100,000128,000
ReasoningYesYes
Tool callingYesYes
File inputYesYes
Inputtext, imagetext, image
Outputtexttext
Released2025-04-162025-08-07