If you use the free version of ChatGPT, you now get GPT-6. OpenAI started rolling out ChatGPT GPT-6 to paying subscribers on Oct. 7 and expanded it to the Free and Go plans on Oct. 8. Free users get a lighter version called GPT-6 Luna, while Plus and Pro subscribers get GPT-6 Sol.
The short version
ChatGPT’s free plan now runs on GPT-6 Luna, and answers can now include buttons, charts and small tools. Paid plans get a bigger model, GPT-6 Sol.
- OpenAI began the rollout on Oct. 7 for Plus, Pro, Business and Enterprise, and on Oct. 8 for Free and Go.
- Free and Go get GPT-6 Luna; Plus, Pro, Business and Enterprise get GPT-6 Sol.
- On OpenAI’s developer price list, Sol costs 20 times as much to run as Luna: $2 versus $0.10 per million tokens of input.
- A new feature called Intelligent UI can answer with charts, forms and simple tools, like a savings calculator.
- OpenAI has not published a separate GPT-6 message limit for free accounts, and the rollout is gradual.
The real shift: ChatGPT is the AI tool most people use, and this changes what a free answer looks like. It also widens the gap between free and paid in a way the plan names do not make obvious.
What ChatGPT GPT-6 changes for free users
Two things change. First, the model underneath. OpenAI says in its announcement that GPT-6 Luna powers the Free and Go tiers and GPT-6 Sol powers Plus, Pro, Business and Enterprise. Second, the look of the answers, through a feature OpenAI calls Intelligent UI.
Intelligent UI lets ChatGPT answer with “fully interactive user interfaces,” in OpenAI’s words: tappable buttons, forms, charts and small tools built right in the chat. Ask how savings could grow and you may get a calculator you can play with instead of a paragraph.
The update applies to the Chat part of ChatGPT. OpenAI says the models used for its Work and Codex tools are not changing.
Luna vs. Sol: how big is the gap?
OpenAI does not say how much smarter Sol is than Luna in everyday chats. But its developer price list gives a clue, because price usually tracks how much computing a model needs. We did the math.
| Model | Who gets it in ChatGPT | Developer price per million tokens in | Per million tokens out |
|---|---|---|---|
| GPT-6 Luna | Free and Go | $0.10 | $0.50 |
| GPT-6 Sol | Plus, Pro, Business, Enterprise | $2 | $10 |
Sol costs 20 times as much as Luna on both counts. That does not mean answers are 20 times better. OpenAI claims Luna, at higher effort settings, matches its older GPT-5.6 Sol at about a hundredth of the cost. It also claims Sol makes about half as many factual mistakes as the model it replaced. Both claims come from OpenAI’s own tests, which it says use conversations where users had flagged errors, so they are not typical chats.
Our take: for everyday questions, writing help and quick explanations, Luna is likely enough. If you rely on ChatGPT for long, hard work tasks, that is where the paid model earns its price.
What still isn’t clear
- Limits. When we checked on Oct. 9, OpenAI had not published a separate GPT-6 message limit for free accounts. Its help page still says Free and Go plans get unlimited everyday text chats, subject to abuse-prevention safeguards, but that page has not caught up with GPT-6 Luna yet. Uploads, image generation, voice and data analysis have their own limits, and OpenAI does not give numbers for those either.
- Timing. The rollout is gradual, so some free accounts may not see GPT-6 yet.
- Where it works. OpenAI’s help page says Intelligent UI works from the Instant setting through Extra High, but not at the Pro setting on top paid plans. It is rolling out on the web and in updated apps. Older versions of the Mac and Windows desktop apps do not show it, so try chatgpt.com in your browser if you do not see it. It does not use up a separate allowance.
What to do now
- Update the ChatGPT app, or open chatgpt.com in your browser, then start a new chat.
- Prefer plain text answers? On the web, turn off Layout and visuals in Settings. OpenAI says some visuals may still appear.
- Treat charts and calculators like any other answer. A neat graph can still be built on a wrong number, so ask ChatGPT where the figures came from and check anything that matters, like money or health.
- Do not upgrade just for GPT-6. Try the free version for a week first and pay only if you keep hitting walls.
- If you are worried about how AI chatbots handle safety, read our coverage of the FTC’s investigation into OpenAI and Anthropic.
Want better answers from any chatbot? Our guide to writing better AI prompts shows how, and our list of the best free apps for students covers other free tools worth trying.
