OpenAI has removed message quotas for free and Go-tier ChatGPT users, allowing unlimited text conversations. Two new models—GPT-5.6 Luna (for free/Go users) and GPT-5.6 Sol (for Plus/Pro users)—significantly reduce error rates (62% and 68% respectively vs. prior versions). A new "Think" button lets free users access deeper processing for complex questions. This aggressive freemium shift reshapes the AI market competitive landscape but limits free users from advanced features like file uploads, image generation, and specialized tools.