GPT-5.6 Luna vs GPT-5.6 Terra
Price, context and benchmark scores side by side — every number from the live model catalogue.
| GPT-5.6 Lunaopenai | GPT-5.6 Terraopenai | |
|---|---|---|
| Input / 1M tokens | $0.500 | $1.25 |
| Output / 1M tokens | $3.00 | $7.50 |
| 1M in + 300K out | $1.40 | $3.50 |
| Context window | 1.1M | 1.1M |
| Intelligence index | 51.2 | 55.0 |
| Coding index | 71.4 | 76.7 |
| Agentic index | 45.6 | 47.4 |
| Cheapest provider | OpenAI | OpenAI |
| Providers serving it | 2 | 2 |
| Weights | Closed | Closed |
| Image input | Yes | Yes |
| Tool calling | Yes | Yes |
| Reasoning mode | Yes | Yes |
| Released | Jul 9, 2026 | Jul 9, 2026 |
Which one to pick
Pick GPT-5.6 Luna if…
- Token cost matters: $3.00 per 1M output vs $7.50.
Pick GPT-5.6 Terra if…
- You want the higher general-intelligence score (55.0).
- Code quality is the priority — it leads on the coding index (76.7).
- You are running agent loops — higher agentic index (47.4).
- You need the bigger context window (1.1M).
FAQ
Is GPT-5.6 Luna better than GPT-5.6 Terra?
GPT-5.6 Terra scores higher on general intelligence (51.2 vs 55.0), while GPT-5.6 Luna is 2.5× cheaper per output token ($3.00 vs $7.50). For code, GPT-5.6 Terra leads (76.7 coding index). GPT-5.6 Terra takes the larger context at 1.1M.
Which is cheaper, GPT-5.6 Luna or GPT-5.6 Terra?
GPT-5.6 Luna, at $3.00 per 1M output tokens versus $7.50. On a 1M input + 300K output workload that is $1.40 against $3.50.
Can I self-host GPT-5.6 Luna or GPT-5.6 Terra?
GPT-5.6 Luna: closed weights, API only. GPT-5.6 Terra: closed weights, API only.