GPT-5
modelMulti-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.
Model Details
Context window 400,000
Variants
| Name | Parameters | Notes |
|---|---|---|
| GPT-5 Main | — | Fast, high-throughput |
| GPT-5 Thinking | — | Reasoning mode |
| GPT-5 Thinking Pro | — | Maximum reasoning accuracy |