Historically, each new generation of OpenAI's models has delivered incremental improvements in factual accuracy, with hallucination rates dropping as the technology matured. However, internal testing and

First reported by TechCrunch, OpenAI's system card detailed the PersonQA evaluation results, designed to test for hallucinations. From the results of this evaluation, o3's hallucination rate is 33 percent,

OpenAI’s o3 and o4-mini models are available now to ChatGPT Plus, Pro, and Team users. Enterprise and education users will get access next week.