GPT-6.1 Terra

We’re introducing GPT-6.1 Terra, a fast, efficient model that combines detailed visual reasoning and precise computer use alongside clearer, more natural writing. A significant step up from GPT‑5.6 Terra, it excels at the communication and computer-based tasks that fill the workday, from drafting proposals and interpreting technical drawings to filling out forms and editing videos. Terra continues to advance the cost-intelligence frontier across our model families, providing a new balance of speed, capability, and cost. Its standard API prices are 50% lower than those of GPT-5.6 Terra and GPT-6.1 Sol, making it practical for developers to automate high-volume work, like reading incoming invoices and entering their details into accounting software. In ChatGPT Work and Codex, your plan goes further with GPT-6.1 Terra—the same usage allowance covers more tasks than with GPT‑5.6 Terra and substantially more than with GPT‑6.1 Sol or GPT‑6 Astra. From visual understanding to action We measured GPT-6.1 Terra’s computer-use capabilities on Agents’ Last Exam, a benchmark of professional tasks that includes turning architectural drawings into a 3D model and reviewing an animated film shot by shot to create a time-coded log for a restoration team. At medium reasoning effort, GPT-6.1 Terra scores 15 percentage points higher than GPT-5.6 Terra at about one-third the cost. It even performs on par with GPT-6 Astra at only one-tenth its price per token. At max effort, Terra is over three times as token efficient as Claude Opus 5.5, and one-fourth its price per token, resulting in a ~9x lower cost per task. Terra is also much quicker, completing tasks over three times faster than both GPT-6 Astra and GPT-6.1 Sol. On MMMU-Pro, a benchmark of visual reasoning, GPT-6.1 Terra outperforms GPT-5.6 Terra at every reasoning setting. It even nearly matches the scores of our most capable frontier model, GPT-6 Astra, and GPT-6.1 Sol at much lower cost. OSWorld 2.1 tests how well AI agents use desktop apps to complete multistep tasks, such as building a 3D model from a technical drawing. At medium reasoning effort, GPT-6.1 Terra surpasses GPT-5.6 Terra’s best score at a fraction of the cost per task. A significant step up on factuality and coding This year, we’ve invested heavily in reducing hallucinations and factual errors produced by our models. On our 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% …