Updated March 26, 2026· Based on independent benchmark data
GPT-5.3 Codex (xhigh) leads in intelligence with a score of 54.0 vs 33.9. DeepSeek V3.1 Terminus (Reasoning) is 4.4x cheaper at $0.40/1M tokens vs $1.75/1M. For speed, GPT-5.3 Codex (xhigh) wins at 72 tok/s vs 0 tok/s.
| Metric | DeepSeek V3.1 Terminus (Reasoning) | GPT-5.3 Codex (xhigh) |
|---|---|---|
| Intelligence Score | 33.9 | 54.0 |
| Coding Score | 33.7 | 53.1 |
| Math Score | 89.7 | N/A |
| Speed (tok/s) | 0 tok/s | 72 tok/s |
| Latency (TTFT) | 0.00s | 83.91s |
| Input Price / 1M tokens | $0.40 | $1.75 |
| Output Price / 1M tokens | $2.00 | $14 |
| Context Window | N/A |
GPT-5.3 Codex (xhigh) outperforms DeepSeek V3.1 Terminus (Reasoning) on the intelligence index with a score of 54.0 compared to 33.9. For coding tasks, GPT-5.3 Codex (xhigh) has the edge with a coding score of 53.1 vs 33.7.
GPT-5.3 Codex (xhigh) generates output significantly faster at 72 tok/s compared to DeepSeek V3.1 Terminus (Reasoning)'s 0 tok/s, making it Infinityx faster for streaming responses. Time to first token is 0.00s for DeepSeek V3.1 Terminus (Reasoning) vs 83.91s for GPT-5.3 Codex (xhigh), which affects perceived responsiveness in interactive applications.
DeepSeek V3.1 Terminus (Reasoning) is more affordable at $0.40/1M input tokens ($2.00/1M output), while GPT-5.3 Codex (xhigh) costs $1.75/1M input ($14/1M output). That makes GPT-5.3 Codex (xhigh) 4.4x more expensive per token, which can add up significantly at scale. For a typical workload of 100 requests per day at 2,000 tokens each, DeepSeek V3.1 Terminus (Reasoning) would cost approximately $2.40/month vs $10.50/month for GPT-5.3 Codex (xhigh) in input costs alone.
Choose DeepSeek V3.1 Terminus (Reasoning) when you need lower cost. Choose GPT-5.3 Codex (xhigh) when you need higher intelligence (54.0), stronger coding performance (53.1), faster output (72 tok/s).
GPT-5.3 Codex (xhigh) scores higher on coding benchmarks (53.1 vs 33.7), making it the better choice for programming tasks.
DeepSeek V3.1 Terminus (Reasoning) is cheaper at $0.40/1M input tokens vs $1.75/1M for GPT-5.3 Codex (xhigh).
GPT-5.3 Codex (xhigh) is faster, producing output at 72 tok/s compared to DeepSeek V3.1 Terminus (Reasoning)'s 0 tok/s.
No, DeepSeek V3.1 Terminus (Reasoning) does not support image input. Neither model supports image input.
Data last synced: March 26, 2026
| N/A |
| Max Output Tokens | N/A | N/A |
| Input Modalities | Text | Text |
| Output Modalities | Text | Text |
| Free Tier | No | No |
It depends on your priorities. GPT-5.3 Codex (xhigh) scores higher on intelligence (54.0), but DeepSeek V3.1 Terminus (Reasoning) may be better for specific use cases like budget-conscious projects or speed-critical applications.