Changes from previous version
Research preview focused on unsupervised scaling versus GPT-4o; API and ChatGPT Pro first, then Plus, Team, Enterprise, and Edu tiers.
Release Summary
OpenAI's largest GPT chat model at launch, scaled for broader knowledge, improved alignment, and more natural conversation with fewer hallucinations than GPT-4o, without o-series chain-of-thought reasoning.
Timeline
February 27, 2025
GPT-4.5 released
OpenAI releases GPT-4.5 as a research preview for ChatGPT Pro and developers, with a companion system card.