GPT-5.1 vs GPT-5.6 Sol
GPT-5.1 Verdict
- GPT-5.6 Sol (high) leads on quality: 68.2 vs 59.6.
- GPT-5.1 is stronger in human preference, instruction following.
- GPT-5.6 Sol (high) is stronger in agents & tools, coding, composite, knowledge, long context, multimodal, reasoning.
- GPT-5.1 is 2.3× cheaper ($3.44 vs $8.00 per 1M blended).
- GPT-5.1 streams 1.6× faster (91 vs 59 tokens per second).
| Metric | GPT-5.1 | GPT-5.6 Sol (high) |
|---|---|---|
| BenchLeader Index | 59.6 | 68.2 |
| Agents & tools score | 55.7 | 87.9 |
| Coding score | 47.1 | 72.4 |
| Composite score | 60.3 | 82.7 |
| Human preference score | 63.3 | – |
| Instruction following score | 71.0 | 67.8 |
| Knowledge score | 66.7 | 73.8 |
| Long context score | 66.6 | 67.4 |
| Multimodal score | 61.8 | 66.4 |
| Reasoning score | 58.7 | 63.3 |
| Blended price $/M | $3.44 | $8.00 |
| Output speed | 91 tok/s | 59 tok/s |
| Time to first answer | 43.1 s | 31.0 s |
| Context window | 400k | 1M |
| Humanity's Last Exam | 23.7% | – |
| Terminal-Bench | 47.6% | – |
| SciCode | 43.3% | 56.9% |
| WeirdML | – | 88.8% |
| APEX-Agents | 17.5% | – |
| GSO-Bench | 13.7% | – |
| Epoch Capabilities Index | 149.7 | – |
| LMArena Text | 1439 | – |
| LMArena Hard Prompts | 1456 | – |
| LMArena Coding | 1475 | – |
| LMArena WebDev | 1341 | – |
| LMArena Vision | 1235 | – |
| AA Intelligence Index | 24.7 | 42.5 |
| IFBench | 72.9% | 69.2% |
| AA-LCR | 80.0% | 81.7% |
| MMMU-Pro | 75.5% | 81.8% |
| AA-Omniscience | 5.4 | 20.4 |
| Terminal-Bench Hard | 45.5% | 62.1% |
| GPQA Diamond (AA) | 87.3% | 92.8% |
| Humanity's Last Exam (AA) | 28.5% | 46.0% |
| SciCode (AA) | – | 57.8% |
| τ²-Bench Telecom (AA) | 81.9% | 83.3% |
| EnigmaEval | – | 37.1% |
| MMMU (validation) | 85.4% | – |
| MMMU-Pro (official) | 76.0% | – |
| ARC-AGI-1 | – | 97.0% |
| ARC-AGI-2 | – | 85.4% |
| ARC-AGI-3 | – | 2.2% |
Data as of 2026-09-10. Best configuration of each model; every score links to its source on the model pages.
GPT-5.1 vs GPT-5.6 Sol: questions
- Is GPT-5.1 better than GPT-5.6 Sol?
- GPT-5.6 Sol (high) leads on quality: 68.2 vs 59.6. The BenchLeader Index combines every independent quality benchmark; GPT-5.6 Sol (high) is ahead overall as of 2026-09-10, but check the category scores for your use.
- Is GPT-5.1 better than GPT-5.6 Sol for coding?
- GPT-5.6 Sol scores higher in coding (72 vs 47 on the category index, where 50 is average).
- Is GPT-5.1 better than GPT-5.6 Sol for agentic tasks?
- GPT-5.6 Sol scores higher in agentic tasks (88 vs 56 on the category index, where 50 is average).
- Which is cheaper, GPT-5.1 or GPT-5.6 Sol?
- GPT-5.1 is cheaper: $3.44 against $8.00 per million tokens, blended at three input tokens per output token.
- Which is faster, GPT-5.1 or GPT-5.6 Sol?
- GPT-5.1 streams faster: 91 against 59 output tokens per second.
- Which has the larger context window?
- GPT-5.6 Sol accepts more context: 1M against 400k tokens.