GPT-5.6 Terra is a balanced model in OpenAI's GPT-5.6 series, positioned between the flagship Sol tier and the cost-efficient Luna tier. It is suited for everyday coding, reasoning, and agentic...
OpenAI: GPT-5.6 Terra — OpenAI. Context window 1,050,000 tokens. API pricing (per 1M tokens): Input $2, Output $12. License: Proprietary. LMArena 1,446. GPQA Diamond 93.3%.
| Provider | OpenAI |
|---|---|
| API model ID | openai/gpt-5.6-terra |
| Tier | Frontier |
| Context window | 1,050,000 tokens |
| Max output | 128,000 tokens |
| License | Proprietary |
| API pricing (per 1M tokens) · Input | $2 |
| API pricing (per 1M tokens) · Output | $12 |
| LMArena | 1,446 (gpt-5.6-terra-xhigh) |
| GPQA Diamond | 93.3% |
LMArena (CC-BY 4.0, best reasoning setting, 2026-10-02) · GPQA Diamond: Epoch AI (CC-BY 4.0)
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