OpenAI ships GPT-6.1 Terra, a smaller model 50% cheaper and more than 3x faster than Astra

OpenAI released GPT-6.1 Terra on October 26, replacing GPT-5.6 Terra at 50% lower pricing: $1 per million input tokens and $5 per million output tokens. OpenAI says it finishes tasks more than 3x faster on average than GPT-6 Astra and GPT-6.1 Sol, and cuts the error rate on internal error-inducing prompts from 53.6% to 16.7% at low reasoning effort. It rolls out in ChatGPT Work, Codex and the API as gpt-6.1-terra, not in regular ChatGPT chat.