Gemini 3.1 Pro Preview Customtools vs gpt-5-pro

Google Gemini 3.1 Pro Preview CustomtoolsOpenAI gpt-5-pro
VendorGoogleOpenAI
Context window1,048,576400,000
Max output65,536272,000
ReasoningYesYes
Tool callingYesYes
File inputYesYes
Inputtext, image, video, audio, filetext, image
Outputtexttext
Released2026-02-192025-08-07