Claude Sonnet 5 vs GPT-5.6 Terra
Claude Sonnet 5 
GPT-5.6 Terra Verdict
- GPT-5.6 Terra (xhigh) leads on quality: 64.4 vs 61.4.
- Claude Sonnet 5 (high) is stronger in knowledge, multimodal, reasoning.
- GPT-5.6 Terra (xhigh) is stronger in agents & tools, coding, composite, human preference, long context, instruction following, maths.
- They cost about the same ($4.00 per 1M blended).
- GPT-5.6 Terra (xhigh) streams 1.3× faster (79 vs 60 tokens per second).
| Metric | Claude Sonnet 5 (high) | GPT-5.6 Terra (xhigh) |
|---|---|---|
| BenchLeader Index | 61.4 | 64.4 |
| Agents & tools score | 61.8 | 69.8 |
| Coding score | 61.6 | 63.7 |
| Composite score | 69.5 | 77.3 |
| Human preference score | 66.2 | 66.7 |
| Knowledge score | 62.4 | 61.0 |
| Long context score | 64.8 | 66.0 |
| Multimodal score | 63.1 | 63.0 |
| Reasoning score | 66.8 | 58.6 |
| Instruction following score | – | 65.3 |
| Maths score | – | 71.0 |
| Blended price $/M | $4.00 | $4.50 |
| Output speed | 60 tok/s | 79 tok/s |
| Time to first answer | 10.0 s | 33.6 s |
| Context window | 1M | 1M |
| SimpleBench | – | 48.9% |
| SciCode | 48.6% | 51.6% |
| WeirdML | 68.8% | – |
| ProofBench | – | 74.0% |
| LMArena Text | 1462 | 1466 |
| LMArena Hard Prompts | 1490 | 1491 |
| LMArena Coding | 1521 | 1519 |
| LMArena WebDev | 1538 | 1521 |
| LMArena Vision | 1278 | 1269 |
| LMArena Agent | 6.3 | 1.5 |
| AA Intelligence Index | 32.0 | 38.2 |
| IFBench | – | 66.3% |
| AA-LCR | 76.7% | 79.0% |
| MMMU-Pro | – | 79.5% |
| AA-Omniscience | -3.7 | -3.0 |
| Terminal-Bench Hard | – | 62.9% |
| GPQA Diamond (AA) | – | 90.8% |
| Humanity's Last Exam (AA) | 35.7% | 41.9% |
| SciCode (AA) | 54.3% | 52.3% |
| τ²-Bench Telecom (AA) | – | 80.4% |
| LiveCodeBench | – | 85.9% |
| MMLU-Pro | – | 86.7% |
| IOI | – | 65.3% |
| CorpFin | – | 65.3% |
| TaxEval | – | 76.2% |
| GPQA Diamond (Vals) | – | 90.9% |
| ARC-AGI-1 | – | 94.0% |
| ARC-AGI-2 | – | 74.2% |
| ARC-AGI-3 | – | 0.7% |
Data as of 2026-09-10. Best configuration of each model; every score links to its source on the model pages.
Claude Sonnet 5 vs GPT-5.6 Terra: questions
- Is Claude Sonnet 5 better than GPT-5.6 Terra?
- GPT-5.6 Terra (xhigh) leads on quality: 64.4 vs 61.4. The BenchLeader Index combines every independent quality benchmark; GPT-5.6 Terra (xhigh) is ahead overall as of 2026-09-10, but check the category scores for your use.
- Is Claude Sonnet 5 better than GPT-5.6 Terra for coding?
- GPT-5.6 Terra scores higher in coding (64 vs 62 on the category index, where 50 is average).
- Is Claude Sonnet 5 better than GPT-5.6 Terra for agentic tasks?
- GPT-5.6 Terra scores higher in agentic tasks (70 vs 62 on the category index, where 50 is average).
- Which is cheaper, Claude Sonnet 5 or GPT-5.6 Terra?
- Claude Sonnet 5 is cheaper: $4.00 against $4.50 per million tokens, blended at three input tokens per output token.
- Which is faster, Claude Sonnet 5 or GPT-5.6 Terra?
- GPT-5.6 Terra streams faster: 79 against 60 output tokens per second.
- Which has the larger context window?
- Both accept 1M tokens of context.