OpenAI has announced that it is removing limits on text-based conversations for all ChatGPT Free users, marking one of the platform's biggest accessibility upgrades after surpassing one billion weekly users.
The company said the new GPT-5.6 Luna model will become the default AI model for Free and Go users, replacing GPT-5.5. The rollout begins this week, with unlimited text chats and a new Think button becoming available next week.
The Think button allows users to request additional reasoning for more complex questions, while limits on file uploads, image generation, voice features and image analysis will remain unchanged.
Upgrades for Plus and Pro users
OpenAI is also introducing an upgraded GPT-5.6 Sol model for ChatGPT Plus and Pro subscribers.
The company said the new model is designed for faster everyday tasks, including answering questions, web research, writing, planning, decision-making and providing advice. It is expected to deliver more concise and reliable responses than its predecessor.
Plus and Pro subscribers are also receiving a thinking slider, enabling them to adjust how much reasoning the AI applies depending on the complexity of a task.
OpenAI noted that the GPT-5.6 Sol model available in ChatGPT is separate from the version used for Codex and Work products.
Improved accuracy
According to OpenAI, internal evaluations found significant improvements in factual accuracy compared with GPT-5.5-Instant.
The company said factual errors were 62% less common with GPT-5.6 Luna and 68% less common with GPT-5.6 Sol.
The updated GPT-5.6 Sol model is available to Plus and Pro users immediately, while the broader rollout for Free and Go users will continue over the coming week.
