GPT-5.5 vs Grok 4.6
GPT-5.5 
Grok 4.6 Verdict
- GPT-5.5 leads on quality: 66.6 vs 63.8.
- GPT-5.5 is stronger in agents & tools, human preference, instruction following, long context, multimodal, reasoning.
- Grok 4.6 (medium) is stronger in coding, composite, knowledge.
- Grok 4.6 (medium) is 3.8× cheaper ($3.00 vs $11.25 per 1M blended).
- GPT-5.5 streams 1.6× faster (88 vs 55 tokens per second).
| Metric | GPT-5.5 | Grok 4.6 (medium) |
|---|---|---|
| BenchLeader Index | 66.6 | 63.8 |
| Agents & tools score | 68.4 | – |
| Coding score | 57.3 | 63.9 |
| Composite score | 77.7 | 83.2 |
| Human preference score | 67.6 | – |
| Instruction following score | 73.3 | – |
| Knowledge score | 73.7 | 77.3 |
| Long context score | 68.8 | 67.1 |
| Multimodal score | 64.9 | – |
| Reasoning score | 69.7 | 62.1 |
| Blended price $/M | $11.25 | $3.00 |
| Output speed | 88 tok/s | 55 tok/s |
| Time to first answer | 62.3 s | 36.7 s |
| Context window | 1.1M | 500k |
| Terminal-Bench | 84.7% | – |
| SimpleBench | 69.0% | – |
| SciCode | – | 54.6% |
| Remote Labor Index | 6.3% | – |
| APEX-Agents | 38.5% | – |
| FrontierCode | 43.0% | – |
| Epoch Capabilities Index | 159.1 | – |
| LMArena Text | 1477 | – |
| LMArena Hard Prompts | 1498 | – |
| LMArena Coding | 1509 | – |
| LMArena WebDev | 1458 | – |
| LMArena Vision | 1296 | – |
| LMArena Agent | 3 | – |
| AA Intelligence Index | 38.6 | 43.0 |
| IFBench | 75.8% | – |
| AA-LCR | 84.3% | 81.0% |
| MMMU-Pro | 79.9% | – |
| AA-Omniscience | 20.5 | 28 |
| Terminal-Bench Hard | 60.6% | – |
| GPQA Diamond (AA) | 93.5% | 93.5% |
| Humanity's Last Exam (AA) | 45.8% | 42.1% |
| SciCode (AA) | 55.8% | 55.9% |
| τ²-Bench Telecom (AA) | 93.9% | – |
| HiL-Bench | 39.7% | – |
| EQ-Bench 4 | 1315 | – |
| Kagi LLM Benchmark | 88.8% | – |
| ARC-AGI-1 | – | 87.5% |
| ARC-AGI-2 | – | 61.3% |
Data as of 2026-09-09. Best configuration of each model; every score links to its source on the model pages.