OpenAI has announced a significant update to ChatGPT that expands access to its latest GPT-5.6 model family. The biggest change is that GPT-5.6 Luna is becoming the default model for Free and Go users, alongside plans to provide unlimited text conversations. A new “Think” option is also being introduced for more challenging questions, although limits will continue to apply to features such as file uploads, images and other tools.

For people who use ChatGPT without a paid subscription, the update could make everyday AI assistance considerably more accessible. Here is what the change means and what free users should know.

What Is GPT-5.6 Luna?

GPT-5.6 Luna is part of OpenAI’s GPT-5.6 model family. OpenAI describes Luna as its fastest and most cost-efficient model in the family, designed to provide useful performance while keeping computational costs lower.

The GPT-5.6 family also includes higher-performance models such as GPT-5.6 Sol and GPT-5.6 Terra, with different models designed for different levels of performance and workloads.

For ordinary ChatGPT users, Luna is particularly important because OpenAI is now expanding it beyond paid environments. GPT-5.6 Luna available for free users means people using the Free plan can receive the newer model as their default experience instead of relying on the previous GPT-5.5 Instant model.

GPT-5.6 Luna Available for Free Users

The most important part of the announcement is the wider availability of Luna.

OpenAI says GPT-5.6 Luna will become the default model for Free and Go users. The rollout is taking place this week, with additional features arriving afterward.

This is significant because users do not necessarily need to upgrade to a paid ChatGPT subscription just to access the newer default model.

For students, writers, professionals, researchers and casual users, this could make ChatGPT more useful for everyday tasks such as:

• Writing and rewriting content
• Brainstorming ideas
• Summarising information
• Explaining difficult concepts
• Creating outlines
• Drafting emails
• Generating marketing ideas
• Basic coding assistance
• Planning projects and activities

The exact experience can still vary depending on the task and available tools, but the default model upgrade represents a major change for the free tier.

Unlimited Text Chats Are Coming

Another major change is the planned removal of standard text-chat limits for Free and Go users.

OpenAI says these users will receive unlimited text chats, subject to abuse-prevention safeguards. However, this does not mean every ChatGPT feature becomes unlimited. Limits will continue to apply to file uploads, images and other tools.

This distinction is important.

A user might be able to continue having ordinary text conversations without hitting the previous message cap, while still encountering restrictions when uploading documents, generating images or using other resource-intensive features.

For people who primarily use ChatGPT as a text-based assistant, however, the change could be substantial.

A New Think Button for Difficult Questions

OpenAI is also bringing a new “Think” button to Free and Go users.

The feature is designed for questions where users want ChatGPT to spend more effort reasoning through a problem. Instead of simply asking a question and accepting the standard response, users will have an additional option for more challenging requests.

This could be useful for tasks involving:

• Complex mathematics
• Multi-step reasoning
• Detailed planning
• Difficult coding problems
• Complicated explanations
• Logic-based questions
• Comparing multiple possibilities

The feature will still operate under OpenAI's abuse-prevention safeguards, and other tool-related limits remain in place.

How Is Luna Different From Paid Models?

Free users should not assume that receiving GPT-5.6 Luna means receiving every capability available to Plus or Pro subscribers.

OpenAI is also updating GPT-5.6 Sol for paid users. Plus and Pro subscribers receive access to an improved Sol model and a reasoning-effort slider that lets them control how much effort ChatGPT puts into generating a response.

In other words, OpenAI is expanding access while maintaining differences between subscription tiers.

Free and Go users get Luna as their default model and expanded text access, while eligible paid users receive access to more advanced model options and additional controls.

What Does This Mean for Students and Professionals?

The update could be particularly useful for people who rely heavily on text-based AI tools but do not want to pay for a subscription.

Students could use ChatGPT to understand concepts, create study plans and practise questions. Writers can use it for brainstorming, editing and structuring articles. Professionals can use it for drafting emails, organising ideas and preparing documents.

The availability of a newer default model also means users may not have to constantly decide which model to select for ordinary tasks.

For many users, the experience becomes simpler: open ChatGPT, type a question and start working.

Are All ChatGPT Features Free Now?

No.

This is one of the most important points to understand about the announcement.

Although OpenAI is expanding text-chat access, file uploads, image features and other tools will continue to have limits for Free and Go users.

Therefore, users who regularly work with large documents, images or specialised tools may still benefit from a paid plan.

The update is primarily about improving the basic text-chat experience and making the newer Luna model available to a much wider audience.

Why OpenAI Is Expanding Free Access

The move comes as competition in the AI industry continues to intensify. OpenAI faces competition from major technology companies as well as newer AI models offering strong performance at lower costs.

Making GPT-5.6 Luna available to free users can help OpenAI keep ChatGPT competitive while allowing the company to maintain more powerful models and features for paying customers. Recent reporting has also highlighted the competitive pressure surrounding pricing and increasingly capable AI models.

Luna's lower operating cost makes it particularly suitable for serving a large number of users.

What Free Users Should Expect

The rollout is happening in stages, so users may not see every feature immediately. OpenAI says GPT-5.6 Luna is becoming the default for Free and Go users, while unlimited text chats and the Think button are scheduled as part of the following rollout.

Users should therefore keep their ChatGPT apps and browser sessions updated and allow time for the changes to reach their accounts.

Final Thoughts

OpenAI's latest move makes the free ChatGPT experience considerably more attractive. The key change is straightforward: GPT-5.6 Luna available for free users as the new default model, combined with expanded access to ordinary text conversations.

The introduction of unlimited text chats and a Think button could make ChatGPT more practical for students, professionals, creators and casual users who rely on AI every day.

At the same time, OpenAI is keeping boundaries between free and paid plans. File uploads, image capabilities and other tools remain subject to limits, while Plus and Pro users continue to receive access to more advanced options.

Overall, the GPT-5.6 Luna rollout represents a meaningful step toward making newer AI capabilities available to a much larger audience—without requiring every user to purchase a subscription.