OpenAI released GPT-6.1 Terra on October 26, with standard API prices 50% lower than GPT-5.6 Terra. It is available to Plus, Pro, Enterprise and Edu users in ChatGPT Work and Codex, and to developers as gpt-6.1-terra. Free users get GPT-5.6 Luna instead.
In OpenAI’s internal error test, the factual-error rate at low reasoning effort fell from 53.6% for GPT-5.6 Terra to 16.7% for the new model. At maximum effort, GPT-6.1 Terra completed 50.3% of Terminal-Bench 4.0 tasks, versus 21.5% for GPT-5.6 Terra. These are OpenAI’s figures; for in-depth research or complex coding, the company still points users to GPT-6.1 Sol or GPT-6 Astra.
