OpenAI updated the version of GPT-5.6 Sol that powers everyday chat in ChatGPT, aiming at shorter, more direct answers and fewer factual mistakes, and added a slider for Plus and Pro users to choose how much thinking goes into each reply. Free and Go users move to GPT-5.6 Luna as the default, with unlimited text chats and a Think button arriving the following week. The updated Sol applies only to chat, and the versions behind Work and Codex are unchanged.
What changed
Free users had a capped number of chats on an older default model, and paid users got different tone and behaviour between quick and deeper answers.
What it unlocks
Paid users can dial how much thinking ChatGPT puts into each answer with a slider, and free users can run unlimited text chats and press a Think button for harder questions.
- 68% fewer error-containing answers (Sol)
- 62% fewer error-containing answers (Luna)
- 1 billion weekly ChatGPT users
What you need to act on it
- Plus or Pro plan for the updated Sol model and slider
- free or Go plan for the new default model, rolling out over the following week
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