Only models with a post-mitigation score of "medium" or below can be deployed. Only models with a post-mitigation score of "high" or below can be developed further.

We’re releasing a research preview of OpenAI GPT‑4.5, our largest and most knowledgeable model yet. Building on GPT‑4o, GPT‑4.5 scales pre-training further and is designed to be more general-purpose than our powerful STEM-focused reasoning models. We trained it using new supervision techniques combined with traditional methods like supervised fine-tuning (SFT) and reinforcement learning from human feedback (RLHF), similar to those used for GPT‑4o. We conducted extensive safety evaluations prior to deployment and did not find any significant increase in safety risk compared to existing models.