OpenAI expands GPT-5.6 Luna to free ChatGPT users, upgrades GPT-5.6 Sol too

OpenAI has officially confirmed improvements for both GPT-5.6 Sol and GPT-5.6 Luna, alongside new features designed to make ChatGPT feel faster, smarter, and more consistent. The changes start rolling out today, with additional updates landing over the next week.

GPT-5.6 Sol becomes smarter for Plus and Pro users

OpenAI says GPT-5.6 Sol now provides more focused responses while making fewer factual mistakes. The company has also tuned the model to avoid unnecessary formatting and keep recommendations clearer during longer conversations.

Another major addition is a new reasoning slider. Plus and Pro users can now decide how much thinking ChatGPT should apply before answering. Lower settings prioritize speed, while higher settings spend more time on planning, research, coding, and complex questions.

OpenAI also says Instant and Thinking experiences now behave much more consistently. Instead of feeling like separate models, both modes should maintain the same tone while adjusting only the depth of reasoning.

Free users receive unlimited chats and a new Think button

Perhaps the biggest announcement targets free users. GPT-5.6 Luna will become the default model for both Free and Go users later this week.
Starting next week, OpenAI will also remove text conversation limits by introducing unlimited text chats for free accounts. For more difficult questions, users can tap a new Think button, giving GPT-5.6 Luna additional reasoning time before responding.

The company notes that abuse protections will still apply, while limits on images, file uploads, and other tools remain unchanged.