Hardware Ready Ready to Bench?
GPT-6 Sol and Luna. OpenAI has expanded the GPT-6 lineup with the new Sol and Luna models, designed to reduce costs and improve accuracy compared to previous versions. The announcement follows shortly after the launch of the Astra model and arrives just minutes after Anthropic’s presentation of Opus 5.5.
OpenAI has announced GPT-6 Sol and GPT-6 Luna, updates to the intermediate and lightweight models of the GPT-6 family, introduced in September with Astra. The company describes them as a practical extension of the same artificial intelligence, made more efficient and accessible in terms of cost.
GPT-6 Sol and Luna: why it matters
The division of tasks follows the schema already seen in the first generation: Sol is dedicated to complex tasks, such as programming and articulated reasoning, while Luna is designed for high-volume office work, including document summaries, information extraction, and rapid answers to specific questions.
The new API price list indicates that the latest models cost half as much as the 5.6 series of Sol and Luna. OpenAI attributes this savings to improvements in caching and inference, not a decrease in model capabilities.
In terms of quality, OpenAI claims significant progress in factual accuracy. According to the company, internal evaluations are based on real conversations (anonymized) where users reported model errors: according to these measurements, GPT-6 Sol commits about half the errors of its predecessor, reaching a level of reliability comparable to Astra but at a lower cost.
The error rate also decreases in code, the company states, without providing precise data. In the press release, OpenAI claims that Sol and Luna handle tasks better than Anthropic’s flagship models, explicitly citing Fable and Opus.
What changes and what are the effects
The announcement arrived just 90 minutes after the release of the new version of Opus (5.5) by Anthropic, highlighting the strong competition between the two labs. It is not certain that benchmark claims will hold up in daily use, where differences between advanced models are often minimal.
The novelties are immediately available in ChatGPT Work and Codex for most paid accounts, as well as via the ChatGPT API. Luna will also be accessible in the desktop app and for users of Free and Go plans. OpenAI expects the rollout to be completed within hours on both the ChatGPT app and website.
Source and further reading on GPT-6 Sol and Luna: original article.
* Content created with the assistance of artificial intelligence systems.