OpenAI Releases GPT-4.5, a "Warm" Generative AI Model, for Paid Plans and APIs | eWeek

OpenAI Releases GPT-4.5, a “Warm” Generative AI Model, for Paid Plans and APIs

Profile photo of Sam Altman.

OpenAI CEO Sam Altman. Image: James Tamim/Creative Commons

Written By
Megan Crouse
Megan Crouse
Feb 28, 2025
2 minute read
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OpenAI has launched GPT‑4.5, its most sophisticated chatbot model yet. The AI is now available in research preview for ChatGPT Pro users and developers. Unlike its predecessors, GPT-4.5 was trained through “supervised learning” to improve pattern recognition, draw connections more intelligently, and generate creative insights without deep reasoning.

The last of the non-reasoning models

GPT-4.5 does not feature advanced reasoning capabilities like OpenAI’s o1 or o3, meaning its responses may lack the depth of its counterparts. It is also not GPT-5, which OpenAI CEO Sam Altman described in early February as a “system that integrates a lot of our technology.” Altman further said that GPT-4.5 will be OpenAI’s final model before transitioning to reasoning-based AI.

Starting Feb. 27, ChatGPT Pro users can access GPT-4.5 through the model picker. Plus and Team users will gain access the week of March 3, followed by Enterprise and Edu users the week of March 10. The model is also available through OpenAI’s Chat Completions API, Assistants API, and Batch API. However, OpenAI cautions that GPT-4.5 may not remain in APIs for long due to its high cost and uncertain role in the company’s GPT-5 roadmap. User feedback will help determine its future availability.

OpenAi emphasized that GPT-4.5 is not a replacement for GPT 4.0.

What is supervised learning?

Supervised learning trains AI models using labeled datasets to improve accuracy and responsiveness. OpenAI describes it as one of two “axes of intelligence,” alongside reasoning. Compared to a reasoning model, a supervised learning model excels at handling general, consumer-oriented queries with more natural responses.

In supervised learning, the AI model is exposed to labeled datasets of inputs and outputs that have been classified according to which output might be a correct answer to the input. Typically, the datasets are labeled in such a way to steer the model toward a specific goal.

Compared to GPT-4, GPT-4.5 might produce “warm and intuitive conversations,” OpenAI said. For example, when asked, “What was the first language?” the model’s response reads like a history documentary:

“Today, linguists study existing languages to understand how they evolved over thousands of years, but the exact identity of humanity’s very first language remains — and will likely always remain — a mystery.”

OpenAI said the improvements achieve that ineffable goal of making it such that interaction with the AI chats “ feels more natural.” GPT-4.5 has an improved “emotional quotient,” or the ability to infer and respond appropriately to human emotions.

However, as generative AI has worked its way into the mainstream, one fundamental problem persists: misinformation.

OpenAI said GPT-4.5 should “hallucinate less” than previous models, but AI-generated content remains vulnerable. Additionally, more naturalistic conversation could be exploited by scammers, especially since people are already using AI to create false rapport with victims.

Megan Crouse

Megan Crouse has a decade of experience in business-to-business news and feature writing, including as first a writer and then the editor of Manufacturing.net. Her news and feature stories have appeared in Military & Aerospace Electronics, Fierce Wireless, TechRepublic, and eWeek. She copyedited cybersecurity news and features at Security Intelligence. She holds a degree in English Literature and minored in Creative Writing at Fairleigh Dickinson University.

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