Please welcome GPT-6 Sol and GPT-6 Luna to the GPT-6 universe.
GPT-6 Sol and Luna build on the advances behind GPT-6 Astra, bringing much of its strengths into faster and more affordable models to support work at scale.
We’ve also made caching and inference more efficient, and we’re passing the savings directly to you: 50% lower API prices for Sol and Luna compared with GPT‑5.6 promotional pricing.
Higher usage limits and lower cost give you more flexibility and room to iterate.
GPT‑6 Sol and Luna build on Astra’s advances in alignment, showing improvements over their GPT-5.6 counterparts.
GPT-6 Sol and Luna roll out today in ChatGPT Work and Codex for Plus, Pro, Business, Enterprise, and Edu users.
Both are also available in the API. Free and Go users can try GPT-6 Luna in the desktop app.
Introducing GPT-6 Sol and Luna
Meet GPT-6 Sol and Luna, two models that bring frontier intelligence to everyday work with different balances of capability and cost.
Model guidance
Per OpenAI API documentation (developers.openai.com):
- GPT-6 Sol (
gpt-6-sol): Built for complex coding and agentic workflows. April 20, 2026 knowledge cutoff. - GPT-6 Luna (
gpt-6-luna): Most efficient model for focused, high-volume tasks. May 18, 2026 knowledge cutoff.
Additional announcements
OpenAI staff member Tibo noted on X: “We have been focusing on efficiency and intelligence for all. Very proud of the team. Only possible when you have incredible models at the top end of the capability that you can then use to make a big difference in everything else.”
OpenAI also announced a banked reset for Plus, Pro, and Business user accounts.
Community benchmarking (Codexometer, September 22, 2026) showed GPT-6-Luna passing dependency scheduler, version resolver, and event processor tasks at roughly 0.0023 API equivalent cost at high effort, with GPT-6-Sol completing the same tasks at roughly 0.058. GPT-5.6-Sol completed the same suite at roughly 0.131.