OpenAI just rolled out an improved version of GPT-5.6 Sol in ChatGPT, along with expanded access for people on the free plan.
What changed
ChatGPT’s GPT-5.6 Sol model has been updated to be more accurate and consistent in its answers. At the same time, free users are getting expanded access, including unlimited everyday chats with GPT-5.6 Luna, a lighter version of the model built for regular, everyday conversations.
Why it matters to you
If you use the free version of ChatGPT, this is good news: you now get more reliable answers from the upgraded Sol model, plus you can chat as much as you want with Luna without hitting a cap. For beginners, this means fewer confusing or inconsistent responses, and less worry about running out of free messages during the day.
What you can do now
Open ChatGPT and try asking a question you’d normally save for later, since everyday chats with Luna are now unlimited on the free plan. If you’ve used ChatGPT before and noticed occasional odd or inconsistent answers, it’s worth trying the same type of question again — the improved Sol model may handle it better now.
Source: official announcement
