OpenAI launches GPT-6.1 Terra, cutting low-effort error rate from 53.6% to 16.7%

OpenAI's GPT-6.1 Terra is the mid-tier member of the 6.1 family, and its headline is factuality. On OpenAI's internal benchmark designed to induce errors, the low-reasoning error rate fell from 53.6% for GPT-5.6 Terra to 16.7%, a drop of nearly 37 points. OpenAI also cites meaningful coding gains, stronger visual reasoning and more accurate computer use.

Distribution was broad from day one. AWS's Matt Wood announced general availability on Amazon Bedrock, where Terra offers a 1M-token context window at half the price of GPT-6.1 Sol, arguing that 'for agents, speed and cost compound.' Developers on HN praised its price-performance at roughly one-tenth the cost of Astra, and OpenAI doubled Pro usage limits days later to handle demand.

Independent evals are mixed but positive. LlamaIndex's Jerry Liu placed Terra 5th on ParseBench, ahead of 6 Sol but behind Opus 5.5 and Astra. It is strong at tables and reading order but weak on layout, charts and formatting, at about 1¢ per page.

The pushback is release fatigue: Terra, Sol and Astra across 6.0 and 6.1 make the lineup hard to follow, and an r/OpenAI thread joking about renaming to 'OpenSI' drew 843 comments. The error benchmark is also internal. Watch for third-party hallucination evals.