OpenAI has introduced updates to ChatGPT that improve GPT-5.6 Sol for Plus and Pro subscribers while giving Free users expanded access to GPT-5.6 Luna, including unlimited text conversations.
GPT-5.6 Luna will become the default model for Free users. OpenAI is also introducing a Think button that lets users activate higher reasoning for more difficult questions.
The unlimited access applies to text chats, allowing Free users to continue conversations without encountering the standard text-message limits previously associated with advanced models.
OpenAI said the expansion is intended to make more capable AI available to a broader group of users while preserving access to additional reasoning when a question requires more thought.
For Plus and Pro subscribers, OpenAI has updated GPT-5.6 Sol to deliver more focused responses and improve factual reliability across everyday conversations.
The model is designed to answer straightforward questions directly while providing more detail for research, planning, writing and other complex tasks.
OpenAI said GPT-5.6 Sol will also use tighter formatting, reduce unnecessary detail and offer helpful corrections when simply agreeing with a user would not be useful.
The same model now supports both quick answers and deeper reasoning for Plus and Pro users, creating a more consistent experience across different types of requests.
A new slider lets subscribers control how much thought ChatGPT applies to each response. Users can choose a lower reasoning level for quick questions or increase it for tasks requiring more extensive analysis.
The updates are intended to improve consistency as people move between simple searches, detailed research, personal advice, planning and complex decision-making within the same conversation.
OpenAI said approximately one billion people use ChatGPT each week for activities ranging from quick questions and web searches to research and complicated decisions.
The company described the changes as part of its broader effort to improve the usefulness and reliability of ChatGPT while making advanced AI capabilities accessible to more people.
