OpenAI rolls out GPT-5.6 Luna as default ChatGPT model, removes text chat limits for free tier users

OpenAI is rolling out new upgrades to ChatGPT across plans, bringing expanded access, new AI models, and an option to enable deeper thinking mode. With the update, free tier users will now get unlimited text chats and the new GPT 5.6 Luna model, replacing GPT-5.5. Whereas Pro and Plus subscribers will be upgraded to GPT-5.6 Sol, offering improved performance and responses.

Alongside these upgrades, OpenAI is also bringing a new slider control for paid ChatGPT users and a “Think” button for free users. Here’s how these upgrades will benefit users.

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GPT‑5.6 Luna, unlimited text access for free ChatGPT users

The GPT-5.6 Luna is part of OpenAI’s GPT-5.6 model family, bringing improved efficiency and performance across tasks. ChatGPT claims that the model is less likely to make factual errors compared to GPT 5.5 Instant.

It is also touted as the fastest and the most affordable model in the GPT-5.6 Family. It supports up to a 1,050,000-token context window and up to 128,000 output tokens. Lastly, it also supports multimodal context, processing both text and image inputs natively.

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One of the biggest upgrades is unlimited text chats without standard rate limits on everyday text conversations. However, limits will be applied for file uploads, images and other tools. In addition, free users also get a new “Think” button that offers higher reasoning capabilities for complex questions.

GPT 5.6 Sol, new reasoning controls and more for Plus and Pro users

OpenAI is rolling out an upgraded version of GPT-5.6 Sol for Plus and Pro ChatGPT users that offers more accurate, focused, and concise answers. OpenAI says that the model “ delivers more focused answers, adapts its level of detail to the question, avoids unnecessary formatting, and offers a helpful correction when simply agreeing wouldn’t be useful.”

The users will also get a new slider in ChatGPT on web, mobile, and desktop, which allows users to choose how much thinking GPT-5.6 Sol should apply before responding. Users can choose from Instant, Medium, High, and Extra High based on the complexity of the prompt. Users can let ChatGPT automatically detect when a prompt requires extra thought and scale up reasoning.