OpenAI CEO Sam Altman announced o3 and o3-mini, the successors to its o1 and o1-mini “reasoning” models. The company is not publicly launching these models and is instead starting public safety testing.

Why call the new model o3, not o2? Well, trademarks may be to blame. According to The Information, OpenAI skipped o2 to avoid a potential conflict with British telecom provider O2.