DeepSeek V3.1 Terminus vs GPT-5 Codex
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 V3.1 Terminus and GPT-5 Codex.
DeepSeek V3.1 Terminus
DeepSeek-V3.1 Terminus is an update to [DeepSeek V3.1](/deepseek/deepseek-chat-v3.1) that maintains the model's original capabilities while addressing issues reported by users, including language consistency and agent capabilities, further optimizing the model's...
GPT-5 Codex
GPT-5-Codex is a specialized version of GPT-5 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
| Specification | DeepSeek V3.1 Terminus | GPT-5 Codex |
|---|---|---|
| Provider | DeepSeek | OpenAI |
| Context Window | 163,840 tokens | 400,000 tokens |
| Agent Suitability | N/A | N/A |
| Time to First Token (TTFT) | N/A | N/A |
| Deployment Model | self hostable | managed api |
| Production Stability | stable | stable |
| API Available | Yes | Yes |
| Released Date | 2025-09-22 | 2025-09-23 |
API Pricing Comparison
Input Price per Million Tokens
DeepSeek V3.1 Terminus
$0.27
GPT-5 Codex
$1.25
Output Price per Million Tokens
DeepSeek V3.1 Terminus
$0.95
GPT-5 Codex
$10.00
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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 V3.1 Terminus Quirks & Gotchas
No developer gotchas reported.
GPT-5 Codex Quirks & Gotchas
No developer gotchas reported.