OpenAI has introduced an improved version of GPT-5.6 Sol for everyday conversations while expanding access to its latest AI models for free ChatGPT users with unlimited text chats. Unlimited text chats for free usersThe company also announced expanded access to its latest AI models for free users with unlimited text chats. “We’re expanding access to our latest models for free users with unlimited text chats using GPT‑5.6 Luna, plus a new Think button for harder questions,” OpenAI said. The improved GPT-5.6 Sol model and the new reasoning slider are available to ChatGPT Plus and Pro users starting today. OpenAI clarified that the version of GPT-5.6 Sol powering Work and Codex is not changing as part of this release.