From www.bleepingcomputer.com: OpenAI has introduced three new reasoning models for ChatGPT subscribers: o3, o4-mini, and o4-mini-high, each with specific usage limits.

Under the Plus plan, users receive up to 50 messages per week for the o3 model, 150 messages daily for o4-mini, and 50 messages daily for o4-mini-high, while the Pro plan offers near unlimited access with some restrictions.

Free users can only access the o4-mini model, and OpenAI has implemented measures to prevent misuse of the service.