GPT-4.5

GPT-4.5 is OpenAI’s most capable general-purpose model yet, advancing the unsupervised learning axis with scaled pretraining, improved alignment, and deeper world knowledge. It leads on factuality benchmarks like SimpleQA with 62.5% accuracy—a 24-point gain over GPT-4o—and cuts hallucination rates nearly in half (37.1% vs. 61.8%). On human evaluations, it’s preferred over GPT-4o in creative (56.8%), professional (63.2%), and everyday (57.0%) use cases, suggesting stronger grasp of nuance, tone, and user intent. While it doesn’t explicitly reason like OpenAI’s o-series models (e.g., o1, o3-mini), it holds its own in STEM tasks, improving AIME '24 performance to 36.7% (up from GPT-4o’s 9.3%) and SWE-Bench Verified to 38.0%, though still trailing o3-mini’s 61.0%. What distinguishes GPT-4.5 isn’t raw logic but conversational feel: it’s more succinct, emotionally intelligent, and better at picking up implicit cues. Its responses sound less scripted and more human—more willing to ask, empathize, or suggest without overexplaining. It supports image inputs and structured outputs, making it a strong fit for tasks like tutoring, design critique, and multi-step agentic workflows. In short, GPT-4.5 doesn’t “think out loud,” but its scaled intuition and alignment make it OpenAI’s most reliable and collaborative assistant to date—especially for users who value factual grounding wrapped in conversational warmth.