Claude Opus 4.6 vs Claude Opus 5.5
Claude Opus 4.6 Verdict
- Claude Opus 5.5 (thinking) leads on quality: 70.7 vs 63.7.
- Claude Opus 4.6 is stronger in agents & tools, coding, human preference, maths.
- Claude Opus 5.5 (thinking) is stronger in multimodal, reasoning, composite, knowledge, long context.
- Claude Opus 5.5 (thinking) is 1.3× cheaper ($8.00 vs $10.00 per 1M blended).
| Metric | Claude Opus 4.6 | Claude Opus 5.5 (thinking) |
|---|---|---|
| BenchLeader Index | 63.7 | 70.7 |
| Agents & tools score | 68.8 | – |
| Coding score | 62.2 | – |
| Human preference score | 64.8 | – |
| Maths score | 68.8 | – |
| Multimodal score | 67.0 | 71.9 |
| Reasoning score | 62.2 | 95.0 |
| Composite score | – | 95.0 |
| Knowledge score | – | 85.0 |
| Long context score | – | 68.5 |
| Blended price $/M | $10.00 | $8.00 |
| Output speed | 37 tok/s | 48 tok/s |
| Time to first answer | 1.6 s | 4.2 s |
| Context window | 1M | 1M |
| GPQA Diamond | 90.5% | – |
| OTIS Mock AIME | 94.4% | – |
| SWE-bench Verified (Epoch) | 78.7% | – |
| Humanity's Last Exam | 19.0% | – |
| Terminal-Bench | 79.8% | – |
| SimpleBench | 67.6% | – |
| Cybench | 93.0% | – |
| Remote Labor Index | 4.2% | – |
| WeirdML | 77.9% | – |
| FrontierCode | 26.6% | – |
| GSO-Bench | 33.3% | – |
| Epoch Capabilities Index | 155.4 | – |
| LMArena Text | 1497 | – |
| LMArena Hard Prompts | 1527 | – |
| LMArena Coding | 1546 | – |
| LMArena WebDev | 1537 | – |
| LMArena Vision | 1312 | – |
| AA Intelligence Index | – | 57.6 |
| AA-LCR | – | 84.7% |
| MMMU-Pro | – | 87.7% |
| AA-Omniscience | – | 46.4 |
| Humanity's Last Exam (AA) | – | 61.4% |
| SciCode (AA) | – | 66.9% |
| HiL-Bench | 38.3% | – |
| EQ-Bench 4 | 1223 | – |
| Kagi LLM Benchmark | 72.4% | – |
| SWE-bench Verified (bash only) | 75.6% | – |
| SWE-bench Verified (any scaffold) | 75.6% | – |
| CritPt | – | 31.7% |
| GDPval (AA) | – | 67.3% |
| MedCode | 48.2% | – |
| MedScribe | 86.7% | – |
| Vibe Code Bench v1.1 | 57.6% | – |
| SWE Atlas: Codebase QnA | 33.3% | – |
| SWE Atlas: Refactoring | 35.6% | – |
| SWE Atlas: Test Writing | 36.7% | – |
| LMArena Maths | 1507 | – |
| LMArena Creative Writing | 1479 | – |
| LMArena Instruction Following | 1500 | – |
| LMArena Multi-turn | 1511 | – |
| LMArena Longer Queries | 1517 | – |
| LMArena Document | 1494 | – |
| Chess Puzzles | 17.0% | – |
| Mystery Game Puzzles | 15.0% | – |
| CL-bench | 20.7% | – |
| CL-bench Life | 13.6% | – |
| METR Time Horizons | 78.9% | – |
| ForecastBench | 60.0% | – |
| GBAEval | 44.1% | – |
| ALE-Bench | 996.5 | – |
| Vending-Bench 2 | 8017.6 | – |
| Terminal-Bench 4.0 (AA) | – | 59.6% |
| AutomationBench | – | 69.5% |
| GDP.pdf | – | 26.2% |
| Harvey LAB | – | 91.2% |
| AA-Omniscience: accuracy | – | 66.2% |
| AA-Omniscience: non-hallucination | – | 41.4% |
| AA-Briefcase | – | 1822 |
Data as of 2026-09-22. Best configuration of each model; every score links to its source on the model pages.
Claude Opus 4.6 vs Claude Opus 5.5: questions
- Is Claude Opus 4.6 better than Claude Opus 5.5?
- Claude Opus 5.5 (thinking) leads on quality: 70.7 vs 63.7. The BenchLeader Index combines every independent quality benchmark; Claude Opus 5.5 (thinking) is ahead overall as of 2026-09-22, but check the category scores for your use.
- Which is cheaper, Claude Opus 4.6 or Claude Opus 5.5?
- Claude Opus 5.5 is cheaper: $8.00 against $10.00 per million tokens, blended at three input tokens per output token.
- Which is faster, Claude Opus 4.6 or Claude Opus 5.5?
- Claude Opus 5.5 streams faster: 48 against 37 output tokens per second.
- Which has the larger context window?
- Both accept 1M tokens of context.