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

Starting this week, free users of ChatGPT will be able to have unlimited text chats without incurring any charges. This change comes as part of OpenAI's efforts to loosen usage limits for its popular AI chatbot.

For paying users, the default model for text-only chats has been upgraded to GPT-5.6 Luna, a lightweight version of the company's newest model family. Luna has been reported to have a 62% lower rate of factual errors compared to the current default model, GPT-5.5 Instant.

New features for both free and paying users include a "Think" button that allows the AI more time to process complex queries, leading to more accurate answers. Plus and Pro subscribers already have access to GPT-5.6 Sol, a heavyweight model designed for everyday tasks such as web research, writing, planning, and decision-making. It is expected to provide more focused and precise responses with less extraneous information.

A new slider tool will be introduced to allow users to adjust the level of technical power they want in their prompts, ranging from GPT-5.6 high to extra high to pro. These improvements are set to be released over the next week, with Luna becoming the new default model.

While the unlimited text chats may benefit those who rely on AI for school or work, there are concerns about potential negative impacts on vulnerable individuals. Some lawsuits have been filed against AI companies due to the excessive use of chatbots leading to mental health issues. OpenAI has added guardrails to its models to prevent romantic roleplay, age-restricted content, and the presentation of itself as a substitute for real-world relationships for users under 18.