GPT-6 Luna
OpenAI · released Sep 22, 2026
| size | small, our estimate, approximate; not disclosed by the manufacturer |
| context window | 1,050,000 tokens |
| longest response | 128,000 tokens |
| knowledge cutoff | May 2026 |
| API price | $0.10 per million input tokens, $0.50 per million output tokens |
| input and output | text and images in, text out |
Manufacturer data (model page, release notes), verified Oct 3, 2026.
Where we tested it
The die
TaskThe model had to roll a fair six-sided die and reply with only the number it rolled.
It rolled a four in all 50 rolls. It does not accept temperature 1 and ran on the maker's default settings.
You'll find the size band and figures for other models on the Tested models page.