Improving GPT-5.6 Sol in ChatGPT—and expanding access for free users

OpenAI has upgraded ChatGPT by introducing GPT-5.6 Sol, which provides enhanced accuracy and consistency. The company is expanding access for free users, who can now enjoy unlimited everyday chats using GPT-5.6 Luna. This significant intelligence update incorporates brand-new default models and new reasoning controls. These improvements aim to elevate the overall user experience by providing more powerful tools and broader availability of advanced models for the entire ChatGPT user base.