OpenAI has just released GPT-4.5, a new version of its flagship large language model. The company claims it is its biggest and best model for all-round chat yet. “It’s really a step forward for us,” says Mia Glaese,

Some researchers think OpenAI's giant and expensive latest model is a sign that tech companies cannot keep making progress by continually scaling up

OpenAI is launching GPT-4.5 today, its newest and largest AI language model. GPT-4.5 will be available as a research preview for ChatGPT Pro users to start. OpenAI is calling the release its “most knowledgeable model yet,” but initially warned that GPT-4.5 is not a frontier model and might not perform as well as o1 or o3-mini.