GPT-6.1 Terra

What is disclosed

OpenAI released GPT-6.1 Terra on 26 October 2026 and describes it as a fast, efficient model for high-volume professional work.¹¹1OpenAI, API changelog, entries of 20 and 26 October 2026, read 30 October 2026. https://developers.openai.com/api/docs/changelog ²²2OpenAI, Addendum to GPT-6 Astra System Card: GPT-6.1 Terra, 26 October 2026, sections on introduction, model data and training, HealthBench and cybersecurity. https://deploymentsafety.openai.com/gpt-6-1-terra It takes text and images and returns text. Audio and video are not supported.³³3OpenAI, GPT-6.1 Terra model page, read 30 October 2026. https://developers.openai.com/api/docs/models/gpt-6.1-terra

The window is 1,050,000 tokens, of which 922,000 can be input. A response can run to 128,000 tokens. The knowledge cutoff is 1 June 2026.³³

The system card addendum says it uses "the same types of data and training as GPT-6 Astra".²² Its size and architecture are not published.

What is new

Terra sits between GPT-6 Luna and GPT-6.1 Sol in price. OpenAI compares it with its predecessor, GPT-5.6 Terra, and highlights image analysis and computer use.²²

On HealthBench Professional, length-adjusted, it scores 62.7, against 57.7 for GPT-5.6 Terra.²² On the plain HealthBench its length-adjusted score is 55.1, which is 1.9 points lower than its predecessor's.²²

OpenAI treats the model as Critical in cybersecurity and High in biological and chemical capability.²² It runs behind the same safeguards stack as Sol and Astra, with probes updated for compatibility.²²

On the Internal Port test of ExploitBench it reaches arbitrary code execution in 24.5% of attempts. GPT-6.1 Sol reaches 21.5% and GPT-6 Astra 31.5%.²²

On Sandbox Bench it solves 5 of 22 targets, against 9 for GPT-6.1 Sol and 10 for GPT-6 Astra.²²

Using it

In the API the model is gpt-6.1-terra.³³

Up to 272K input tokens, Standard pricing is $1 per million input tokens and $5 per million output tokens. Cached input costs $0.05.⁴⁴4OpenAI, API pricing, Standard table, read 30 October 2026. https://developers.openai.com/api/docs/pricing. Arithmetic: 1 / 2 = 0.5; 1 / 0.10 = 10; 5 / 0.50 = 10; 1 x 2.5 = 2.5. Above 272K, input doubles to $2 and output rises to $7.50.⁴⁴

That is half the price of GPT-6.1 Sol, at $2 and $10 for input and output.⁴⁴ It is ten times the price of GPT-6 Luna, at $0.10 and $0.50.⁴⁴

On 20 October OpenAI added 12-hour prompt caching, with cache writes at 2.5 times the input price.¹¹ For Terra a 30-minute cache write costs $1.25 and a 12-hour write $2.50.⁴⁴