# OpenAI launches GPT-4.5 as a research preview
Event date: 2025-02-27
OpenAI has launched GPT-4.5, describing it as its newest and largest language model while also warning that it is not a frontier model. The supplied Verge report says the company is making the system available first as a research preview for ChatGPT Pro users. OpenAI has framed the release as its most knowledgeable model yet and said it should feel more natural, warmer and more useful in everyday conversation than earlier versions.
The model's positioning matters as much as the release itself. OpenAI says GPT-4.5 is better at writing, programming and solving practical problems, and that it has improved world knowledge and a more refined personality. At the same time, the company is careful not to oversell it. According to the report, OpenAI explicitly says GPT-4.5 is not a frontier model and may not outperform the reasoning-focused o1 or o3-mini systems on some tasks. That makes it a product launch with a built-in caveat: bigger and more polished, but not necessarily more capable across the board.
The Verge also reported that OpenAI had trained GPT-4.5 using new supervision techniques, together with supervised fine-tuning and reinforcement learning from human feedback. The company says the model hallucinates less than GPT-4o and slightly less than o1, which is important because reliability has become one of the central competitive metrics in AI. Raphael Gontijo Lopes, an OpenAI researcher, said human testers preferred GPT-4.5 over GPT-4o in essentially every category when judging warmth and collaborative style. That kind of feedback suggests OpenAI is trying to move beyond pure benchmark chasing and toward a model that is easier to use in ordinary work.
The rollout plan is staged. OpenAI says GPT-4.5 will reach Plus and Team users the following week and then Enterprise and Edu users after that. The model is also already available in Microsoft's Azure AI Foundry alongside systems from Stability, Cohere and Microsoft. In the background, the company is already talking about GPT-5, which Sam Altman has described as a system that integrates a lot of OpenAI's technology and will include the o3 reasoning model. That sequence shows OpenAI is trying to turn a family of models into a more layered product stack rather than relying on a single all-purpose release.
Altman said the model is giant and expensive and warned that it will not crush benchmarks. That comment is useful because it strips away some of the mythology around model launches. GPT-4.5 appears to be a step toward better general interaction, less hallucination and smoother writing, not an announcement that the AI race has reached a final stage. For users, the immediate question is not whether the model sounds impressive, but whether it actually helps them do work better, faster and with fewer mistakes.
The launch also fits into OpenAI's broader product story. The company is no longer presenting each release as a stand-alone breakthrough. Instead, it is layering models with different strengths, from writing and conversational polish to stronger reasoning systems intended for harder tasks. GPT-4.5 appears to sit in that middle layer: a larger, friendlier and less hallucinatory model that is useful on its own but also serves as a bridge toward whatever GPT-5 is meant to become.
