Lineage · Since 2024

The OpenAI o1 lineage

OpenAI's reasoning-first model line, which spends inference-time compute on a private chain of thought before answering.

Generation 1 · Dec 5, 2024

OpenAI o1

OpenAI o1 is a reasoning model that thinks through a problem internally before replying, trading latency and cost for much higher accuracy on maths, science and difficult programming tasks. It reached general availability in December 2024 and set the template for later reasoning models.

Closed200K ctxMultimodalExtended step-by-step reasoning before answeringCompetition-level mathematics and physics problems