Claude Sonnet 4.5 vs GPT-5.6 Sol
Claude Sonnet 4.5 
GPT-5.6 Sol Verdict
- GPT-5.6 Sol (high) leads on quality: 66.0 vs 57.9.
- Claude Sonnet 4.5 (high) is stronger in human preference, reasoning.
- GPT-5.6 Sol (high) is stronger in coding, agents & tools, composite, instruction following, knowledge, long context, multimodal.
- Claude Sonnet 4.5 (high) is 1.3× cheaper ($6.00 vs $8.00 per 1M blended).
- GPT-5.6 Sol (high) streams 1.5× faster (61 vs 40 tokens per second).
| Metric | Claude Sonnet 4.5 (high) | GPT-5.6 Sol (high) |
|---|---|---|
| BenchLeader Index | 57.9 | 66.0 |
| Coding score | 56.4 | 72.4 |
| Human preference score | 65.3 | – |
| Reasoning score | 66.4 | 63.3 |
| Agents & tools score | – | 82.5 |
| Composite score | – | 75.7 |
| Instruction following score | – | 64.7 |
| Knowledge score | – | 70.4 |
| Long context score | – | 65.1 |
| Multimodal score | – | 65.5 |
| Blended price $/M | $6.00 | $8.00 |
| Output speed | 40 tok/s | 61 tok/s |
| Time to first answer | 1.2 s | 12.6 s |
| Context window | 1M | 1.1M |
| SciCode | – | 56.9% |
| WeirdML | – | 88.8% |
| LMArena Text | 1456 | – |
| LMArena Hard Prompts | 1487 | – |
| LMArena Coding | 1520 | – |
| LMArena WebDev | 1393 | – |
| AA Intelligence Index | – | 42.5 |
| IFBench | – | 69.2% |
| AA-LCR | – | 81.7% |
| MMMU-Pro | – | 81.8% |
| AA-Omniscience | – | 20.4 |
| Terminal-Bench Hard | – | 62.1% |
| GPQA Diamond (AA) | – | 92.8% |
| Humanity's Last Exam (AA) | – | 46.0% |
| SciCode (AA) | – | 57.8% |
| τ²-Bench Telecom (AA) | – | 83.3% |
| EnigmaEval | – | 37.1% |
| SWE-bench Verified (bash only) | 71.4% | – |
| ARC-AGI-1 | – | 97.0% |
| ARC-AGI-2 | – | 85.4% |
| ARC-AGI-3 | – | 2.2% |
Data as of 2026-09-13. Best configuration of each model; every score links to its source on the model pages.
Claude Sonnet 4.5 vs GPT-5.6 Sol: questions
- Is Claude Sonnet 4.5 better than GPT-5.6 Sol?
- GPT-5.6 Sol (high) leads on quality: 66.0 vs 57.9. The BenchLeader Index combines every independent quality benchmark; GPT-5.6 Sol (high) is ahead overall as of 2026-09-13, but check the category scores for your use.
- Is Claude Sonnet 4.5 better than GPT-5.6 Sol for coding?
- GPT-5.6 Sol scores higher in coding (72 vs 56 on the category index, where 50 is average).
- Which is cheaper, Claude Sonnet 4.5 or GPT-5.6 Sol?
- Claude Sonnet 4.5 is cheaper: $6.00 against $8.00 per million tokens, blended at three input tokens per output token.
- Which is faster, Claude Sonnet 4.5 or GPT-5.6 Sol?
- GPT-5.6 Sol streams faster: 61 against 40 output tokens per second.
- Which has the larger context window?
- GPT-5.6 Sol accepts more context: 1.1M against 1M tokens.