Deepseek v4 Pro vs GPT-5.5
Deepseek v4 Pro 
GPT-5.5 Verdict
- GPT-5.5 leads on quality: 66.7 vs 60.4.
- Deepseek v4 Pro (high) is stronger in coding, maths.
- GPT-5.5 is stronger in human preference, reasoning, agents & tools, composite, instruction following, knowledge, long context, multimodal.
| Metric | Deepseek v4 Pro (high) | GPT-5.5 |
|---|---|---|
| BenchLeader Index | 60.4 | 66.7 |
| Coding score | 59.4 | 57.2 |
| Human preference score | 65.8 | 67.9 |
| Maths score | 66.2 | – |
| Reasoning score | 66.0 | 70.1 |
| Agents & tools score | – | 68.5 |
| Composite score | – | 77.8 |
| Instruction following score | – | 73.6 |
| Knowledge score | – | 73.9 |
| Long context score | – | 68.8 |
| Multimodal score | – | 64.9 |
| Blended price $/M | – | $11.25 |
| Output speed | – | 85 tok/s |
| Time to first answer | – | 58.6 s |
| Context window | – | 1.1M |
| GPQA Diamond | 90.9% | – |
| OTIS Mock AIME | 95.6% | – |
| Terminal-Bench | – | 84.7% |
| SimpleBench | – | 69.0% |
| SciCode | 46.4% | – |
| Remote Labor Index | – | 6.3% |
| WeirdML | 46.5% | – |
| APEX-Agents | – | 38.5% |
| FrontierCode | – | 43.0% |
| Epoch Capabilities Index | – | 159.1 |
| LMArena Text | 1460 | 1477 |
| LMArena Hard Prompts | 1482 | 1498 |
| LMArena Coding | 1505 | 1509 |
| LMArena WebDev | 1580 | 1458 |
| LMArena Vision | – | 1296 |
| LMArena Agent | – | 3 |
| AA Intelligence Index | – | 38.6 |
| IFBench | – | 75.8% |
| AA-LCR | – | 84.3% |
| MMMU-Pro | – | 79.9% |
| AA-Omniscience | – | 20.5 |
| Terminal-Bench Hard | – | 60.6% |
| GPQA Diamond (AA) | – | 93.5% |
| Humanity's Last Exam (AA) | – | 45.8% |
| SciCode (AA) | – | 55.8% |
| τ²-Bench Telecom (AA) | – | 93.9% |
| HiL-Bench | – | 39.7% |
| EQ-Bench 4 | – | 1315 |
| Kagi LLM Benchmark | – | 88.8% |
Data as of 2026-09-10. Best configuration of each model; every score links to its source on the model pages.
Deepseek v4 Pro vs GPT-5.5: questions
- Is Deepseek v4 Pro better than GPT-5.5?
- GPT-5.5 leads on quality: 66.7 vs 60.4. The BenchLeader Index combines every independent quality benchmark; GPT-5.5 is ahead overall as of 2026-09-10, but check the category scores for your use.
- Is Deepseek v4 Pro better than GPT-5.5 for coding?
- Deepseek v4 Pro scores higher in coding (59 vs 57 on the category index, where 50 is average).