GPT-5.6 Terra vs Kimi K3
GPT-5.6 Terra 
Kimi K3 Verdict
- Kimi K3 leads on quality: 66.5 vs 64.2.
- GPT-5.6 Terra (xhigh) is stronger in agents & tools, composite, instruction following, reasoning.
- Kimi K3 is stronger in coding, human preference, knowledge, long context, maths, multimodal.
- GPT-5.6 Terra (xhigh) is 1.3× cheaper ($4.50 vs $6.00 per 1M blended).
- GPT-5.6 Terra (xhigh) streams 2.5× faster (93 vs 37 tokens per second).
| Metric | GPT-5.6 Terra (xhigh) | Kimi K3 |
|---|---|---|
| BenchLeader Index | 64.2 | 66.5 |
| Agents & tools score | 69.6 | 67.5 |
| Coding score | 63.7 | 64.9 |
| Composite score | 77.1 | 74.1 |
| Human preference score | 66.3 | 71.2 |
| Instruction following score | 65.0 | – |
| Knowledge score | 60.9 | 68.1 |
| Long context score | 66.0 | 71.1 |
| Maths score | 71.0 | 78.1 |
| Multimodal score | 63.0 | 65.1 |
| Reasoning score | 58.2 | – |
| Blended price $/M | $4.50 | $6.00 |
| Output speed | 93 tok/s | 37 tok/s |
| Time to first answer | 32.5 s | 57.7 s |
| Context window | 1M | 1.0M |
| SimpleBench | 48.9% | – |
| SciCode | 51.6% | 58.7% |
| APEX-Agents | – | 39.3% |
| FrontierCode | – | 44.2% |
| ProofBench | 74.0% | 87.0% |
| Epoch Capabilities Index | – | 157.6 |
| LMArena Text | 1466 | – |
| LMArena Hard Prompts | 1491 | – |
| LMArena Coding | 1519 | – |
| LMArena WebDev | 1521 | – |
| LMArena Vision | 1269 | – |
| LMArena Agent | 1.5 | – |
| LiveBench | – | 79.2% |
| LiveBench Reasoning | – | 90.7% |
| LiveBench Coding | – | 81.5% |
| LiveBench Agentic Coding | – | 62.2% |
| LiveBench Mathematics | – | 84.4% |
| LiveBench Data Analysis | – | 78.7% |
| LiveBench Language | – | 85.5% |
| AA Intelligence Index | 38.2 | 43.8 |
| IFBench | 66.3% | – |
| AA-LCR | 79.0% | 88.7% |
| MMMU-Pro | 79.5% | 80.5% |
| AA-Omniscience | -3.0 | 19.7 |
| Terminal-Bench Hard | 62.9% | – |
| GPQA Diamond (AA) | 90.8% | 93.5% |
| Humanity's Last Exam (AA) | 41.9% | 46.9% |
| SciCode (AA) | 52.3% | 59.5% |
| τ²-Bench Telecom (AA) | 80.4% | – |
| LiveCodeBench | 85.9% | – |
| MMLU-Pro | 86.7% | – |
| IOI | 65.3% | – |
| LegalBench | – | 86.0% |
| CorpFin | 65.3% | 71.6% |
| TaxEval | 76.2% | 75.7% |
| Terminal-Bench 2.1 (Vals) | – | 80.9% |
| SWE-bench (Vals) | – | 93.4% |
| GPQA Diamond (Vals) | 90.9% | 92.9% |
| Vals Index | – | 57.8 |
| EQ-Bench 4 | – | 1339 |
| ARC-AGI-1 | 94.0% | – |
| ARC-AGI-2 | 74.2% | – |
| ARC-AGI-3 | 0.7% | – |
Data as of 2026-09-09. Best configuration of each model; every score links to its source on the model pages.