Can You Use GPT-6 Luna for Free?

Who gets GPT-6 Luna

OpenAI's announcement says Sol and Luna are available in ChatGPT Work and Codex for Plus, Pro, Business, Enterprise and Edu users, and that Free and Go users can access GPT-6 Luna in the desktop app. It also says the models were not yet available in the ordinary Chat view.

In the API neither model is free. Luna is listed at $0.10 per million input tokens and $0.50 per million output tokens, half of the promotional price of GPT-5.6 Luna.

What the picker looked like

In ChatGPT Work on a paid plan, the model list showed Default, GPT-6 Astra, GPT-6 Sol, GPT-6 Luna, GPT-5.6 Sol, GPT-5.6 Terra, GPT-5.6 Luna and GPT-5.5. Picking Luna by name gave five effort levels: Light, Medium, High, Extra High and Max.

Free users should expect a smaller menu. We did not see it, so we will not guess at its layout.

What Luna is good for in a small business

Luna is the model OpenAI built for fast, high-volume work. We gave it the same bakery launch brief as the larger models. It kept every fact right, invented nothing, and wrote three usable photo prompts and a caption.

Then we asked it for 100 image prompts in one go. It delivered exactly 100, each 26 to 33 words and each with a no-text clause, in under two minutes. That is the kind of job a free desktop allowance suits: lists, variants and first drafts.

What Luna will not do

Luna writes text. It does not draw. OpenAI lists text as its only output, and image generation happens only when an app or developer connects a separate image tool.

On September 21 we also found OpenAI's plan page saying image generation isn't available on the Free plan. If that still holds, a free Luna session can plan a picture but will not make it.

• Is GPT-6 Astra free? (September 21)
• Can GPT-6 Sol or Luna make images?

A free workflow that works

Use Luna to write the plan, then make the picture in a tool that charges per image. In Ciyo, Luna's prompt goes into the Image Generator; at 4:5, 1K and GPT Image 2.5 Flare, one image cost 2 credits in our test.

Ciyo does not run GPT-6 Luna itself, so the step between the two is a copy and paste.

Write five different image prompts for one 4:5 Instagram photo of [product] for [shop name]. Each prompt is one sentence of 20 to 35 words. Vary the angle, setting and light. Every prompt must say the image contains no words, letters or logos. List anything you had to guess about the product under 'Assumptions'.

OpenAI's rollout note

ChatGPT's own account announced the rollout plans on launch day. It names the paid plans; the free desktop access comes from the longer announcement.