Today, OpenAI has announced that ChatGPT users on the free version (as well as the cheapest Go paid tier) will get unlimited text chats with no automatic switching to a lesser model. Speaking of models, GPT-5.6 Luna, the smallest of the three GPT-5.6 models released in July, will become the default for the free and Go users, taking over from the ancient (in AI terms) GPT-5.5 Instant.
The switch to GPT-5.6 Luna will take place at some point this week, while the unlimited text chats will be available next week, which is also when free and Go users will get access to a new Think button. This will let you pick how much “thought” ChatGPT puts into its responses. While there will be no more limits for text chats, free and Go users will still encounter limits for file uploads and image generation.
OpenAI is also improving the flagship GPT-5.6 Sol model, which is only available to those who pay for the Plus or Pro tiers. The updates are “designed to give you more direct responses, use tighter formatting, and avoid extra detail when it does not help”, the company says. If you just have a quick question, you’ll get “a direct answer with the context you need”, while for multi-step planning or research, you will see “a fuller response that keeps the main recommendation clear”.
The new GPT-5.6 Sol is also “designed to make fewer mistakes”, especially when it comes to numbers, dates, sources, rules, or assumptions. OpenAI says that in an internal evaluation of financial, medical, and legal prompts requiring factual detail, responses containing at least one factual error were about 68% less common with the new GPT-5.6 Sol compared to GPT-5.5 Instant.
The Think button will be a slider for Plus and Pro subscribers, going from “instant” to “pro” levels of “thinking” while keeping the same tone and style. OpenAI says you can keep it quick for “everyday questions” and move it up for “planning, research, writing, coding, or decisions that need more thought”.
Interestingly, the version of GPT-5.6 Sol that’s powering ChatGPT Work and Codex isn’t changing as part of this update. The new model described above is “optimized for everyday chats”, so it will only be available in the Chat experience.