ChatGPT moves every plan to GPT-6: Sol for paid plans, Luna for Free and Go

OpenAI began moving all ChatGPT users to GPT-6 on October 7, 2026. Its Deployment Safety Hub says GPT-6 is launching “to everyone in ChatGPT, across free and paid plans globally,” and that the new models replace GPT-5.6 Sol and GPT-5.6 Luna in ChatGPT.

Which plan gets which model

Plan	Model in Chat	Rollout starts
Plus, Pro, Business, Enterprise	GPT-6 Sol	October 7, 2026
Free, Go	GPT-6 Luna	October 8, 2026

The rollout notice says the release changes Chat only. The models in ChatGPT Work and Codex stay the same: OpenAI’s safety page says those surfaces still run the GPT-6 Sol and Luna versions released in September.

In the API, Luna is OpenAI’s cheapest GPT-6 model, at $0.10 input and $0.50 output per 1M tokens, while Sol costs $2 and $10, and Astra $10 and $50. So free ChatGPT runs on the lowest-priced GPT-6 model, and paid plans on the middle one.

What “Intelligent UI” means

The announcement posted on OpenAI’s developer forum says GPT-6 can build answers from text, visuals and interactive parts: charts, clickable controls, and small in-chat tools such as calculators or games. Plain text stays available when it is the better format. GPT-6 can also start answering while it is still reasoning. OpenAI reports that GPT-6 Instant starts answering questions that need web search 44% sooner on average than GPT-5.6 Instant, measured as time to the first answer, not total time.

Safety rating

OpenAI’s safety page treats both models as “High” capability in cybersecurity and in biological and chemical domains, with the same safeguards as GPT-5.6.

What the notes don’t say

None of the pages we read mention plan prices or message limits for the new models. If you are deciding between Free, Go and Plus, check the current limits on ChatGPT’s plan page; the model difference is now Luna versus Sol.