OpenAI's GPT-6.1 Terra halves standard API prices and doubles Terminal-Bench 4.0 solve rate

OpenAI introduced GPT-6.1 Terra, a fast, efficient model that pairs detailed visual reasoning and precise computer use with clearer, more natural writing for workday tasks such as drafting proposals, interpreting technical drawings, filling out forms and editing videos. OpenAI describes it as a significant step up from GPT-5.6 Terra and as continuing to advance the cost-intelligence frontier across its model families. On Agents' Last Exam, a benchmark of professional tasks including turning architectural drawings into a 3D model and reviewing an animated film shot by shot, GPT-6.1 Terra at medium reasoning effort scores 15 percentage points higher than GPT-5.6 Terra at about one-third the cost.

Cost is central to the release: standard API pricing is $1 per million input tokens, $0.05 per million cached input tokens and $5 per million output tokens. OpenAI states these standard API prices are 50% lower than those of GPT-5.6 Terra and GPT-6.1 Sol, making high-volume automation such as reading invoices into accounting software practical for developers. On Agents' Last Exam, GPT-6.1 Terra at medium reasoning effort performs on par with GPT-6 Astra at one-tenth its price per token; at max effort it is over three times as token efficient as Claude Opus 5.5 at one-fourth its price per token, a roughly 9x lower cost per task.

Factuality and coding improve together: on OpenAI's internal benchmark of error-inducing prompts, the error rate at low reasoning effort falls from 53.6% with GPT-5.6 Terra to 16.7% with GPT-6.1 Terra. OpenAI says it invested heavily this year in reducing hallucinations and factual errors, and at maximum effort the error rate falls by 18 percentage points to 4.3%, nearly matching GPT-6 Astra and GPT-6.1 Sol. On Terminal-Bench 4.0, which tests coding agents on command-line problems, GPT-6.1 Terra at maximum reasoning effort solves 50.3% of tasks, more than double GPT-5.6 Terra's published 21.5%; OpenAI adds that GPT-6.1 Sol and GPT-6 Astra remain the better choice for the most complex coding tasks.

GPT-6.1 Terra is available starting today to Plus, Pro, Enterprise and Edu users in ChatGPT Work and Codex, and to developers through the OpenAI API as gpt-6.1-terra. OpenAI says the same usage allowance in ChatGPT Work and Codex covers more tasks with GPT-6.1 Terra than with GPT-5.6 Terra and substantially more than with GPT-6.1 Sol or GPT-6 Astra. On Terminal-Bench-Science 0.1, which tests agents using code for research tasks such as tracking cell divisions in a time-lapse video, GPT-6.1 Terra at max reasoning surpasses GPT-6.1 Sol at lower cost and comes within five points of Opus 5.5 at less than one-fifth the estimated cost.

This report draws on OpenAI's release note, covering the model's positioning, benchmark scores, safety evaluation conclusions, pricing and availability; the benchmark scores and cost ratios are OpenAI's own, and safety detail is deferred to its system card.

OpenAI says GPT-6.1 Terra meets the Critical threshold in cybersecurity under its Preparedness Framework and maintains the protections developed for GPT-6 Astra; its alignment and prompt-injection resistance conclusions come from OpenAI's own evaluations, with more detail in the system card.