GPT-6.1 Terra

GPT-6.1 Terra is OpenAI's efficiency-tier model in the GPT-6.1 generation, released 2026-10-26 to ChatGPT (Work), Codex and the API (model id gpt-6.1-terra). It is the first Terra-class model since GPT-5.6 Terra and targets fast, cheap computer use and everyday agentic work: it reads what is on screen, acts across apps, and handles visual reasoning tasks. Priced at $1 / $5 per 1M input/output tokens ($0.05 cached input) - half of GPT-5.6 Terra and GPT-6.1 Sol. OpenAI says it performs on par with GPT-6 Astra at about a tenth of the per-token price and finishes tasks 3x+ faster than Astra and GPT-6.1 Sol; Terminal-Bench 4.0 (max effort) 50.3% vs 21.5% for GPT-5.6 Terra. Artificial Analysis: Coding Agent Index v2.0 48 (Sol 54, Luna 31), AA-Omniscience hallucination rate 38% (down from 88%). OpenAI still recommends Sol or Astra for the hardest coding work. Context window per trackers ~1.05M (not confirmed in launch materials).