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 1M 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 | 1M |
Terra | $2.50 | $15 | 1M |
Luna | $1 | $6 | 1M |
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 your monthly token volume to see what each tier would cost.
| Tier | Input cost | Output cost | Monthly total |
|---|---|---|---|
| Sol | $5.00 | $6.00 | $11.00 |
| Terra | $2.50 | $3.00 | $5.50 |
| Luna | $1.00 | $1.20 | $2.20cheapest |
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 5× on input and 5× 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.
Sources
- OpenRouter — GPT-5.6 Sol — retrieved 2026-07-17
- OpenRouter — GPT-5.6 Terra — retrieved 2026-07-17
- OpenRouter — GPT-5.6 Luna — retrieved 2026-07-17
Figures on this page last checked against these sources on 2026-07-17. Vendors change pricing and specs without notice — if a number here disagrees with the vendor's own page, trust the vendor.