Claude Opus 4.6 vs GPT-5.5 Pro
Claude Opus 4.6 
GPT-5.5 Pro Verdict
- GPT-5.5 Pro (xhigh) leads on quality: 67.1 vs 63.7.
- Claude Opus 4.6 is stronger in agents & tools, coding, human preference, multimodal.
- GPT-5.5 Pro (xhigh) is stronger in maths, reasoning.
- Claude Opus 4.6 is 6.8× cheaper ($10.00 vs $67.50 per 1M blended).
- Claude Opus 4.6 streams 8.5× faster (34 vs 4 tokens per second).
| Metric | Claude Opus 4.6 | GPT-5.5 Pro (xhigh) |
|---|---|---|
| BenchLeader Index | 63.7 | 67.1 |
| Agents & tools score | 67.8 | – |
| Coding score | 62.3 | – |
| Human preference score | 64.7 | – |
| Maths score | 68.7 | 74.5 |
| Multimodal score | 67.0 | – |
| Reasoning score | 62.6 | 80.1 |
| Blended price $/M | $10.00 | $67.50 |
| Output speed | 34 tok/s | 4 tok/s |
| Time to first answer | 1.7 s | 3.5 s |
| Context window | 1M | 1.1M |
| GPQA Diamond | 90.5% | – |
| FrontierMath Tiers 1–3 | – | 87.7% |
| FrontierMath Tier 4 | – | 78.0% |
| 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% | – |
| APEX-Agents | 32.4% | – |
| FrontierCode | 26.6% | – |
| GSO-Bench | 33.3% | – |
| Epoch Capabilities Index | 155.3 | – |
| LMArena Text | 1497 | – |
| LMArena Hard Prompts | 1527 | – |
| LMArena Coding | 1546 | – |
| LMArena WebDev | 1537 | – |
| LMArena Vision | 1312 | – |
| 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% | – |
| ARC-AGI-1 | – | 95.0% |
| ARC-AGI-2 | – | 84.2% |
| CritPt | – | 30.6% |
| 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% | – |
| LMCA | – | 53.9% |
| DTBench | – | 96.0% |
| ForecastBench | 60.0% | – |
| GBAEval | 44.1% | – |
| ALE-Bench | 996.5 | – |
| Vending-Bench 2 | 8017.6 | – |
Data as of 2026-09-19. Best configuration of each model; every score links to its source on the model pages.
Claude Opus 4.6 vs GPT-5.5 Pro: questions
- Is Claude Opus 4.6 better than GPT-5.5 Pro?
- GPT-5.5 Pro (xhigh) leads on quality: 67.1 vs 63.7. The BenchLeader Index combines every independent quality benchmark; GPT-5.5 Pro (xhigh) is ahead overall as of 2026-09-19, but check the category scores for your use.
- Which is cheaper, Claude Opus 4.6 or GPT-5.5 Pro?
- Claude Opus 4.6 is cheaper: $10.00 against $67.50 per million tokens, blended at three input tokens per output token.
- Which is faster, Claude Opus 4.6 or GPT-5.5 Pro?
- Claude Opus 4.6 streams faster: 34 against 4 output tokens per second.
- Which has the larger context window?
- GPT-5.5 Pro accepts more context: 1.1M against 1M tokens.