Summary
GPT-6 Sol and Luna: where each one lives, what it costs, and which tier to point an agent at
The useful content here is routing and access, not capability. Sol and Luna are not more powerful than Astra — the video says so plainly — and the reason to care about them is that they cost half as much and burn through your plan's usage limits far more slowly.
"GPT-6 Sol + Luna Just Changed AI Agents" by Julian Goldie SEO — Watch on YouTube →
The three-tier split
| Tier | Built for | List price / 1M tokens |
|---|---|---|
| GPT-6 Astra | Frontier results | Highest |
| GPT-6 Sol | Complex coding and professional work | $2 in / $10 out |
| GPT-6 Luna | Fast, efficient everyday work at scale | $0.10 in / $0.50 out |
Both new tiers landed at roughly half the API price of the GPT-5.6 models they replace — Sol down from $4/$20, Luna down from $0.20/$1.20. Sol is also offered in light and medium sizes inside the ChatGPT Work model picker. Rates we track for all of these are in the cost calculator.
Where you can actually get them
- ChatGPT Work and Codex — rolling out to Plus, Pro, Business, Enterprise and Edu. Rollout was gradual through the day, so a client that does not show the models yet is probably just waiting its turn rather than broken.
- The API — available immediately.
- Free and Go users — can try GPT-6 Luna in the desktop app. This is the no-cost route in.
- In plain ChatGPT (outside the Work section) there are no tier dials — the model picker lives in Work.
The stated reason to switch is that Astra exhausts plan usage limits quickly. Pointing routine agent work at Sol or Luna gets far more done on the same subscription. Both are also described as cheaper on long conversations thanks to better caching — which is exactly the shape of an agent's workload.
What actually improved, and what did not
The claimed wins: better performance on business tasks across apps, coding and computer use; Sol gets facts wrong about half as often as GPT-5.6; shorter answers with less jargon and more honesty about what was actually checked; and better caching for agents and long conversations.
The honest part, and the reason this page exists rather than a hype summary: he pulls up a third-party index and shows that the improvement is a mix of gains and regressions. Sol edges past GPT-5.6 Sol; Luna is roughly level with its predecessor. On that index Opus 5.5 sits at the top, ahead of Fable 5.1 and GPT-6 Astra Max. Treat any single index as one data point — see our aggregated leaderboard for the spread across sources.
Key Takeaways
- Neither new tier is more capable than Astra. They are cheaper and easier on usage limits — route accordingly.
- Luna in the desktop app is the free way to evaluate the new generation before committing.
- Sol at $2/$10 is the sensible default for bulk agent work; keep Astra or Opus for the hard calls.
- Better prompt caching makes these tiers disproportionately cheaper for long-running agent sessions.
- A staged rollout means "my client does not list it" is usually a timing problem, not a configuration one.
Measured head-to-heads against these models: Opus 5.5 vs Sol and Opus 5.5 vs Astra.
What you can actually set up from this
Extracted from the video's own transcript — the specifics the original summary left out.
Reproducible steps
- Find the models in ChatGPT Work
In the video, the ChatGPT Work model picker shows GPT-6 Sol and GPT-6 Luna. Sol offers light and medium settings and then switches to Astra-lite, which is more powerful than Sol; Luna is the lightest setting, for non-frontier work. Regular ChatGPT has no such dials.
- Check Codex for the update
At recording time Codex did not show the new models yet; the speaker checked for updates to the latest version and expected the rollout later that day.
- Route by job
Astra for the best frontier-level results, Sol for complex coding and professional work, Luna for fast everyday work at scale such as a quick chatbot-style agent.
- Side-by-side test
The speaker ran the same racing-game prompt on Luna and Sol Medium. Both worked; Luna's version was basic with limited movement, while Sol's front page and gameplay were clearly better.
Gotchas
- Availability as stated in the video: rolling out in ChatGPT Work and Codex for Plus, Pro, Business, Enterprise and Edu users, available in the API, and free and Go users can try Luna in the desktop app.
- Prices quoted from Artificial Analysis in the video (not checked against OpenAI's pricing page): Sol dropped from $4 input / $20 output to $2 / $10 per million tokens; Luna from $0.20 / $1.20 to $0.10 / $0.50.
- Hallucination figures quoted in the video: Sol Max 92% down to 60%, Luna 93% down to 77%. The speaker also says the Artificial Analysis ranking barely moved: the new models are not more powerful than Astra.
- The speaker's own verdict: the bigger update of the day was Opus 5.5, which he places first on the Artificial Analysis ranking at that time.
- Sol is described as half the API price of GPT 5.6 and, per OpenAI as relayed in the video, wrong on facts about half as often.
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