Gemini 3.1 Pro Preview vs GPT-5.3 Codex

Google Gemini 3.1 Pro PreviewOpenAI GPT-5.3 Codex
VendorGoogleOpenAI
Context window1,048,576400,000
Max output65,536128,000
ReasoningYesYes
Tool callingYesYes
File inputYesYes
Inputtext, image, video, audio, filetext, image, file
Outputtexttext
Released2026-02-192026-02-05