DeepSeek V4 Flash vs GPT-5.6 Terra Pro
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 DeepSeek V4 Flash and GPT-5.6 Terra Pro.
DeepSeek V4 Flash
DeepSeek V4 Flash is an efficiency-optimized Mixture-of-Experts model from DeepSeek with 284B total parameters and 13B activated parameters, supporting a 1M-token context window. It is designed for fast inference and...
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
Technical Specifications
| Specification | DeepSeek V4 Flash | GPT-5.6 Terra Pro |
|---|---|---|
| Provider | DeepSeek | OpenAI |
| Context Window | 1,048,576 tokens | 1,050,000 tokens |
| Agent Suitability | 86/100 | N/A |
| Time to First Token (TTFT) | 120 ms | N/A |
| Deployment Model | managed api | managed api |
| Production Stability | stable | beta |
| API Available | Yes | Yes |
| Released Date | 2026-04-24 | 2026-07-09 |
API Pricing Comparison
Input Price per Million Tokens
DeepSeek V4 Flash
$0.09
GPT-5.6 Terra Pro
$2.50
Output Price per Million Tokens
DeepSeek V4 Flash
$0.18
GPT-5.6 Terra Pro
$15.00
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.
DeepSeek V4 Flash Quirks & Gotchas
- ▸Best cost-per-token ratio of any hosted API — ideal for high-throughput pipelines
- ▸Lower agentic performance vs V4 Pro — route complex tool calls accordingly
GPT-5.6 Terra Pro Quirks & Gotchas
No developer gotchas reported.