OpenAI · API pricing
GPT-5.6 pricing: Sol, Terra and Luna
GPT-5.6 ships in three tiers at three price points. All three became generally available on July 9, 2026, all three carry a 1.05M token context window, and all three share a February 2026 knowledge cutoff — so the only thing you are trading between them is capability against cost.
Price per 1M tokens
| Tier | Input / 1M | Output / 1M | Context |
|---|---|---|---|
Sol | $5 | $30 | 1.05M |
Terra | $2 | $12 | 1.05M |
Luna | $0.20 | $1.20 | 1.05M |
Output tokens cost 6× input tokens on every tier, so for most applications the output column is the one that decides your bill.
What it costs at your volume
Cost calculator
Enter monthly volume and the typical prompt size. The applicable context tier is selected automatically.
| Tier | Input cost | Output cost | Monthly total |
|---|---|---|---|
| Sol | $5.00 | $6.00 | $11.00 |
| Terra | $2.00 | $2.40 | $4.40 |
| Luna | $0.20 | $0.24 | $0.44cheapest |
Estimates only — list prices, before any caching discount, batch pricing, or enterprise agreement.
Which tier should you use?
The spread from Luna to Sol is 25× on input and 25× on output. Since the context window is identical across tiers, the question is never “which one fits my prompt” — it is only whether a given task needs the flagship's reasoning. A common pattern is to route bulk classification and chat to Luna, keep everyday coding on Terra, and reserve Sol for the reasoning-heavy work where a wrong answer is expensive.
What does GPT-5.6 Sol Ultrafast cost?
No public Ultrafast price has been published. Cerebras and OpenAI describe it as a limited preview for a select group of customers, expanding over time. The published performance claim is up to 750 output tokens per second for GPT-5.6 Sol, not a new model rate card. Until OpenAI posts a price, the standard Sol prices above are the only public figures we can put in a budget.
Sources
- OpenAI — API pricing — retrieved 2026-08-14
- OpenAI — API pricing — retrieved 2026-08-14
- OpenAI — API changelog (July 30: Terra costs 20% less) — retrieved 2026-08-14
- OpenAI — API pricing — retrieved 2026-08-14
- OpenAI — API changelog (July 30: Luna costs 80% less) — retrieved 2026-08-14
- Cerebras — Accelerating GPT-5.6 Sol Ultrafast with OpenAI — retrieved 2026-08-14
Figures on this page last checked against these sources on 2026-08-14. Vendors change pricing and specs without notice — if a number here disagrees with the vendor's own page, trust the vendor.