GPT Astra, GPT Sol, GPT Luna and GPT Aurora (red, blue, green) explained
GPT Astar TeamWhat are GPT-6 Astra, GPT-6 Sol and GPT-6 Luna, how much do they cost, and what are the unannounced GPT Aurora red, blue and green models? A plain-English guide, plus how GPT Astar compares.
Short answer: GPT Astra, GPT Sol and GPT Luna are the three tiers of OpenAI's GPT-6 family. Astra is the flagship, Sol is the mid tier and Luna is the budget tier. GPT Aurora red, GPT Aurora blue and GPT Aurora green are three unannounced OpenAI model IDs (aurora-red-alpha, aurora-blue-alpha, aurora-green-alpha) that appeared in OpenAI's API on October 17, 2026. OpenAI has not said what they are.
GPT Astar is a different product. It is an independent AI assistant with its own model family, and it is not affiliated with OpenAI. More on that below.
Last updated: October 18, 2026. These models are new and details change quickly; we'll update this page as OpenAI publishes more.
GPT Astra vs GPT Sol vs GPT Luna at a glance
| Model | Tier | Released | API price (input / output per 1M tokens) | Best for |
|---|---|---|---|---|
| GPT-6 Astra | Flagship | Sep 3, 2026 | $10 / $50 | The hardest multi-step work, computer use, advanced science and math |
| GPT-6 Sol | Mid tier | Sep 22, 2026 | $2 / $10 | Coding, debugging, data analysis, agents |
| GPT-6 Luna | Budget | Sep 22, 2026 | $0.10 / $0.50 | High-volume routine tasks such as summarising and extraction |
| GPT Aurora red / blue / green | Unknown | Spotted Oct 17, 2026 | Not published | Unannounced — no official information |
What is GPT Astra?
GPT Astra (GPT-6 Astra) is OpenAI's flagship GPT-6 model, released on September 3, 2026. OpenAI positions it as its most capable model for coding, computer use and cybersecurity, and it is the most expensive of the three at $10 per million input tokens and $50 per million output tokens. Its API model ID is gpt-6-astra. It isn't included on ChatGPT's Free or Go plans.
What is GPT Sol?
GPT Sol (GPT-6 Sol) is the middle tier of GPT-6, released on September 22, 2026. It costs $2 per million input tokens and $10 per million output tokens — a fifth of Astra — and targets everyday professional work such as coding, debugging, data analysis and agents. Sol has a context window of about 1 million tokens. A newer GPT-6.1 Sol keeps the same price with cheaper cached input.
What is GPT Luna?
GPT Luna (GPT-6 Luna) is the budget tier of GPT-6, released alongside Sol on September 22, 2026. At $0.10 per million input tokens and $0.50 per million output tokens it is about a hundredth of Astra's price, and it is built for high-volume, routine jobs like summarisation, classification and data extraction. Like Sol, it has a context window of about 1 million tokens.
What are GPT Aurora red, GPT Aurora blue and GPT Aurora green?
GPT Aurora red, GPT Aurora blue and GPT Aurora green refer to three model IDs — aurora-red-alpha, aurora-blue-alpha and aurora-green-alpha — that appeared in OpenAI's API model list on October 17, 2026, created within about 90 seconds of each other. As of October 18, 2026, OpenAI has not announced or documented them, and reports disagree on whether they are still listed.
What they are is still guesswork. Some observers think the colours mark different sizes or speed tiers; others link them to coding (Codex) variants or to an earlier anonymous "Aurora Alpha" model. None of this is confirmed. Treat any claim about Aurora red, blue or green benchmarks or pricing as rumour until OpenAI publishes official details.
Astra, Sol or Luna: which one do you need?
- Choose GPT Luna if you process large volumes of simple text and cost matters most.
- Choose GPT Sol for most professional work — code, analysis and agents — at a fraction of Astra's price.
- Choose GPT Astra only for the hardest problems where the extra capability is worth 5× Sol's price.
All three are sold by OpenAI through ChatGPT business plans, the OpenAI API and cloud platforms.
Is GPT Astar the same as GPT Astra?
No. The names are similar, but GPT Astar is an independent AI assistant and is not affiliated with OpenAI. It does not offer GPT-6 Astra, Sol, Luna or Aurora.
What GPT Astar does offer is an affordable everyday assistant for people who don't need an enterprise model:
- Seven specialist models — Astar Flash, Lingo and Mini (free), and Astar Ultra, Coder, Writer and Long (Pro) — for writing, coding, study, long documents and translation in 100+ languages.
- 20 free messages every day, no credit card.
- Pro for $9.90 a month, about half of a typical $20 AI subscription.
If your work truly needs GPT-6 Astra's computer use or frontier science performance, use OpenAI directly. For emails, homework, code questions, translation and summaries, try GPT Astar free.
FAQ
Is GPT Astra the same as GPT-6 Astra?
Yes. "GPT Astra" is the common short name for OpenAI's GPT-6 Astra, the flagship of the GPT-6 family.
Which is cheaper, GPT Sol or GPT Luna?
GPT Luna. It costs $0.10 / $0.50 per million input / output tokens, versus $2 / $10 for GPT Sol.
Are GPT Aurora red, blue and green released?
Not officially. They appeared as model IDs in OpenAI's API on October 17, 2026, but OpenAI has not announced, documented or priced them.
Can I use GPT Astra, Sol or Luna on GPT Astar?
No. GPT Astar runs its own model family and is not affiliated with OpenAI.