GPT-5.6 Terra Pro vs GPT-5.2-Codex
Detailed technical comparison between GPT-5.6 Terra Pro (OpenAI) and GPT-5.2-Codex (OpenAI). Review live API token pricing, context window capabilities, time-to-first-token latency, and verified benchmark scores side-by-side.
Comparison Snapshot
GPT-5.6 Terra Pro
1,050,000 tokensTie
Equal CapabilityTie
Equal SpeedGPT-5.2-Codex
$1.75 / MTokGPT-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-5.2-Codex
GPT-5.2-Codex is an upgraded version of GPT-5.1-Codex optimized for software engineering and coding workflows. It is designed for both interactive development sessions and long, independent execution of complex engineering tasks....
Technical Specifications
🏆 = Superior Spec| Specification | GPT-5.6 Terra Pro | GPT-5.2-Codex |
|---|---|---|
| Provider | OpenAI | OpenAI |
| Context Window | 1,050,000 tokens🏆 | 400,000 tokens |
| Agent Suitability | Not yet benchmarked | Not yet benchmarked |
| Time to First Token (TTFT) | No public TTFT data | No public TTFT data |
| Deployment Model | managed api | managed api |
| Production Stability | Beta Access (est.) | Stable GA (est.) |
| API Available | Yes | Yes |
| Released Date | 2026-07-09 | 2026-01-14 |
API Pricing Comparison
Input Price per Million Tokens
GPT-5.6 Terra Pro
$2.50
GPT-5.2-Codex
$1.75
Output Price per Million Tokens
GPT-5.6 Terra Pro
$15.00
GPT-5.2-Codex
$14.00
💡 Cost Ratio: GPT-5.2-Codex is 1.4x cheaper per input token than GPT-5.6 Terra Pro.
Want to test both models live?
Run side-by-side prompt benchmarks in our dynamic multi-model Sandbox. Compare execution speeds, latency metrics, and compute actual costs in real-time.
Benchmark Performance Metrics
Standardized Scores (0–100%)Scores show verified raw accuracy percentages across standardized AI evaluation suites. Higher bars indicate superior performance in that domain.
GPT-5.6 Terra Pro Quirks & Gotchas
No developer gotchas reported.
GPT-5.2-Codex Quirks & Gotchas
No developer gotchas reported.
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