OpenAI o3 is a reflective generative pre-trained transformer model developed by OpenAI as a successor to OpenAI o1 for ChatGPT. It is designed to devote additional deliberation time when addressing questions that require step-by-step logical reasoning. On January 31, 2025, OpenAI released a smaller model, o3-mini, followed on April 16 by o3 and o4-mini. From Wikipedia
