GPT-6 Luna

GPT-6 Luna is an OpenAI model released on September 22, 2026, together with GPT-6 Sol.

Lab: OpenAI
Release date: September 22, 2026
Status: Generally available
API model ID: gpt-6-luna
Context window: 1,050,000 tokens
Max output: 128,000 tokens

OpenAI released GPT-6 Luna on September 22, 2026, together with GPT-6 Sol. In the API it is gpt-6-luna; OpenAI’s model docs list a 1,050,000-token context window, 128,000 max output tokens, text and image input with text output, and a May 18, 2026 knowledge cutoff. In ChatGPT it is available to Plus, Pro, Business, Enterprise and Edu users in ChatGPT Work and Codex, and Free and Go users can use it in the desktop app.

Our coverage: OpenAI releases GPT-6 Sol and GPT-6 Luna.

Modalities: Text and image input; text output
Knowledge cutoff: May 18, 2026
Availability: ChatGPT Work and Codex for Plus, Pro, Business, Enterprise and Edu users; Free and Go users in the desktop app; OpenAI API (Responses and Chat Completions).
Official source: openai.com
Last checked: October 5, 2026

Questions

When was GPT-6 Luna released?

OpenAI released GPT-6 Luna on September 22, 2026, together with GPT-6 Sol.

Can free users use GPT-6 Luna?

Yes. Free and Go users can use it in the ChatGPT desktop app.

What is the knowledge cutoff of GPT-6 Luna?

OpenAI’s model docs list a May 18, 2026 knowledge cutoff, with a 1,050,000-token context window.

Source

Release dates, model IDs and limits come from each lab’s own announcement, changelog, documentation or deprecations page, linked on every model with the date it was last checked. How we pick and check sources: editorial standards.