GPT-5

model
OpenAI

Multi-component system combining a fast model, reasoning model, and router into a single interface. 400K token context. Replaced GPT-4o, o3, o4-mini, and GPT-4.1 as the default ChatGPT model. Architecture undisclosed.

GPT-5 unified fast inference and deep reasoning in one model, with variants spanning from nano (lightweight) to thinking-pro (maximum reasoning). AA Intelligence Index: 45. Proprietary.

AnnouncementArtificial AnalysisOpenRouter

Model Details

Parameters (est.) ~ 4.1T
Context window 400,000
AA Intelligence 45

Variants

Name Parameters Notes
GPT-5 Main — Fast, high-throughput
GPT-5 Thinking — Reasoning mode
GPT-5 Thinking Pro ~ 4.1T Maximum reasoning accuracy
frontierreasoningmultimodal

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