ChatGPT Goes Unlimited: Free Tier Gets GPT-5.6 Luna Access

OpenAI has announced global changes to the accessibility of its chatbot. Users on the free version and the Go plan are receiving unlimited text chats. Now, the neural network will no longer automatically switch to a less capable model, ensuring a consistent quality of interaction.

Switching to GPT-5.6 Luna: What Has Changed for Free Users

A key update for free and Go tier users is the replacement of the aging GPT-5.5 Instant model with the current GPT-5.6 Luna. This is the most compact version within the GPT-5.6 series introduced in July. The transition to the new language model is expected to occur this week.

In addition to the engine update, a new “Think” button will become available next week. This tool allows users to manually adjust the chatbot’s “reasoning” depth when generating a response. Despite the removal of text chat restrictions, limits on image generation and file uploads remain in place for these plans.

Upgrades to the Flagship GPT-5.6 Sol

Plus and Pro subscribers receive an updated version of their primary model—GPT-5.6 Sol. The update focuses on enhancing response quality: the neural network now provides more direct phrasing, uses clearer formatting, and avoids unnecessary details that do not contribute to the core point.

According to internal OpenAI reports, GPT-5.6 Sol handles facts significantly better: when solving financial, medical, and legal tasks, the error rate has decreased by approximately 68% compared to the GPT-5.5 Instant model.

The New “Think” Button and Functionality for Pro Users

Premium subscribers get access to “Think” depth control, which is implemented as a slider. Users can regulate the model’s effort from “instant” (for daily questions) to “professional” (for complex tasks like coding, deep research, planning, or strategy development), while maintaining a consistent conversational style.

Important Notes: Work and Codex Remain Unchanged

It is important to note that this update specifically concerns the chat experience. The GPT-5.6 Sol version used by ChatGPT Work and Codex remains unchanged, as the announced improvements were optimized exclusively for user-dialogue formats.