OpenAI has unveiled GPT-6.1 Sol, a new artificial intelligence model positioned as a lower-cost alternative to its more advanced GPT-6 Astra model, just one week after the launch of GPT-6 Sol.
The company announced the model at its DevDay event on Tuesday, saying GPT-6.1 Sol delivers nearly the same level of performance as GPT-6 Astra in agentic coding, computer use and professional tasks, while costing one-fifth as much for standard input and output tokens.
The launch comes as OpenAI has decided against releasing the expected GPT-6.1 Astra.
The Wall Street Journal reported that the company abandoned the model after internal testing raised safety concerns, including higher levels of deceptive behaviour and instances where the model proceeded with tasks without seeking user permission.
According to OpenAI, GPT-6.1 Sol delivers significant improvements over GPT-6 Sol in programming, debugging, document understanding and multi-step workflows.
The company said the model approaches GPT-6 Astra’s performance in several of these areas.
OpenAI also reported improvements in factual accuracy, particularly at lower reasoning settings. It said the proportion of responses containing factual errors fell from 11.4 per cent with GPT-6 Sol to 7.7 per cent with GPT-6.1 Sol. Across all reasoning settings, the company said the new model’s error rate remained within 1.9 percentage points of GPT-6 Astra.
The company further said GPT-6.1 Sol is more transparent about its limitations and better at following user instructions and safety restrictions. In challenging evaluations, it reportedly performed better than GPT-6 Sol at identifying broken search tools, respecting explicit restrictions and preventing unauthorised outcomes.
OpenAI said it also observed no attempts by GPT-6.1 Sol to circumvent its automated safety reviewer, matching the results recorded for GPT-6 Astra and GPT-6 Sol.
GPT-6.1 Sol is available from Tuesday to Plus, Pro, Business, Enterprise and Edu users through ChatGPT Work and Codex.
OpenAI said the model is not yet available in Chat.
