GPT-5.6 Terra Pro vs GPT-5 Nano
How do these models stack up? Below is an expert side-by-side comparison of specifications, context window capacity, live pricing per million tokens, and standardized benchmark scores for GPT-5.6 Terra Pro and GPT-5 Nano.
GPT-5.6 Terra Pro
GPT-5.6 Terra Pro is the same underlying model as [GPT-5.6 Terra](https://openrouter.ai/openai/gpt-5.6-terra), served with `reasoning.mode` set to `pro` for higher-quality responses on complex tasks. Learn more in OpenAI's docs: https://developers.openai.com/api/docs/guides/reasoning#reasoning-mode
GPT-5 Nano
GPT-5-Nano is the smallest and fastest variant in the GPT-5 system, optimized for developer tools, rapid interactions, and ultra-low latency environments. While limited in reasoning depth compared to its larger...
Technical Specifications
| Specification | GPT-5.6 Terra Pro | GPT-5 Nano |
|---|---|---|
| Provider | OpenAI | OpenAI |
| Context Window | 1,050,000 tokens | 400,000 tokens |
| Agent Suitability | N/A | N/A |
| Time to First Token (TTFT) | N/A | N/A |
| Deployment Model | managed api | managed api |
| Production Stability | beta | stable |
| API Available | Yes | Yes |
| Released Date | 2026-07-09 | 2025-08-07 |
API Pricing Comparison
Input Price per Million Tokens
GPT-5.6 Terra Pro
$2.50
GPT-5 Nano
$0.05
Output Price per Million Tokens
GPT-5.6 Terra Pro
$15.00
GPT-5 Nano
$0.40
Want to test both models live?
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Benchmark Performance Metrics
Scores show the raw performance percentages verified across key evaluation suites. Higher bars indicate superior accuracy and capability in that domain.
GPT-5.6 Terra Pro Quirks & Gotchas
No developer gotchas reported.
GPT-5 Nano Quirks & Gotchas
No developer gotchas reported.