DeepSeek DeepSeek V3.1 Terminus vs OpenAI GPT-5.1-Codex-Max — side-by-side specs.
DeepSeek DeepSeek V3.1 Terminus | OpenAI GPT-5.1-Codex-Max | |
|---|---|---|
| Overview | ||
| Company | DeepSeek | OpenAI |
| Release date | Sep 22 2025 | Nov 19 2025 |
| Model type | — | — |
| Open source | Yes | No |
| Specifications | ||
Parameters | — | — |
Context window | — | — |
| Benchmarks | ||
| Timeline | ||
| Release gap | DeepSeek V3.1 Terminus shipped 58 days before GPT-5.1-Codex-Max | |
DeepSeek V3.1 Terminus and GPT-5.1-Codex-Max don't publish scores on any of the same benchmarks, so there's no direct head-to-head comparison. DeepSeek V3.1 Terminus shipped 58 days before GPT-5.1-Codex-Max, so benchmark comparisons should account for the intervening progress.
DeepSeek V3.1 Terminus is an open-source / open-weight model; GPT-5.1-Codex-Max is proprietary.
Direct benchmark comparisons are unavailable — DeepSeek V3.1 Terminus and GPT-5.1-Codex-Max don't publish scores on any of the same benchmarks.