OpenAI launches GPT-6.1 Terra, a faster, cheaper medium-sized model

What happened: OpenAI released GPT-6.1 Terra, upgrading its medium-sized model from GPT-5.6. Terra had been left out when GPT-6 Sol and Luna launched the previous month, 9to5Mac reported.

The numbers: API pricing is $1 per million input tokens and $5 per million output. OpenAI says the price is 50% lower than GPT-5.6 Terra and GPT-6.1 Sol, according to BleepingComputer. 9to5Mac reports the 50% cut against GPT-5.6 Terra only. OpenAI also says Terra completes tasks more than 3 times as quickly as GPT-6 Astra and GPT-6.1 Sol, and performs on par with Astra at one-tenth its price per token.

In their words: OpenAI's announcement, as quoted by BleepingComputer, described the model this way: "We're introducing GPT-6.1 Terra, a fast, efficient model that combines detailed visual reasoning and precise computer use."

The context: On Agents' Last Exam, Terra scored 15 percentage points higher than GPT-5.6 Terra at medium reasoning effort, at about one-third the cost. On Terminal-Bench 4.0 it scored 50.3% at maximum reasoning effort, against 21.5% for GPT-5.6 Terra. On OpenAI's internal benchmark of error-inducing prompts, the error rate at low reasoning effort fell from 53.6% with GPT-5.6 Terra to 16.7%.

The catch: OpenAI still recommends GPT-6.1 Sol or GPT-6 Astra for the most complex coding tasks. The error-rate figures come from OpenAI's internal benchmark, not an independent test. Artificial Analysis separately reported a large drop in hallucination rate on its own benchmark.

Who's affected: Developers can call the model as gpt-6.1-terra in the API. It is also available now in ChatGPT Work and Codex.

Why it matters: OpenAI's lineup has four tiers, from Luna at the lowest capability to Astra at the highest. Terra is the second of four tiers, below Sol and Astra.

What's next: In ChatGPT, the model is still rolling out to Plus, Pro, Enterprise and Edu users.