Claude Opus 4.8 vs Claude Sonnet 5.5
Claude Opus 4.8 Verdict
- Claude Sonnet 5.5 (max) leads on quality: 67.6 vs 62.4.
- Claude Opus 4.8 (max) is stronger in instruction following, knowledge.
- Claude Sonnet 5.5 (max) is stronger in agents & tools, coding, composite, long context, maths, reasoning.
- Claude Sonnet 5.5 (max) is 2.5× cheaper ($4.00 vs $10.00 per 1M blended).
- Claude Sonnet 5.5 (max) streams 2.4× faster (141 vs 58 tokens per second).
| Metric | Claude Opus 4.8 (max) | Claude Sonnet 5.5 (max) |
|---|---|---|
| BenchLeader Index | 62.4 | 67.6 |
| Agents & tools score | 56.5 | 69.5 |
| Coding score | 59.6 | 69.8 |
| Composite score | 65.4 | 72.6 |
| Instruction following score | 62.0 | – |
| Knowledge score | 67.2 | 65.4 |
| Long context score | 64.0 | 66.6 |
| Maths score | 68.4 | 72.9 |
| Reasoning score | 69.2 | 81.1 |
| Blended price $/M | $10.00 | $4.00 |
| Output speed | 58 tok/s | 141 tok/s |
| Time to first answer | 33.7 s | 487.1 s |
| Context window | 1M | 1M |
| GPQA Diamond | 91.0% | 95.6% |
| FrontierMath Tiers 1–3 | 80.0% | 88.8% |
| FrontierMath Tier 4 | 56.1% | 80.5% |
| OTIS Mock AIME | 98.3% | 100.0% |
| SimpleQA Verified | 53.0% | 46.5% |
| Terminal-Bench | 23.6% | 61.8% |
| OSWorld-Verified 2.0 | 20.6% | – |
| SciCode | 53.5% | 61.0% |
| APEX-Agents | 48.9% | 75.5% |
| ProofBench | 69.0% | 100.0% |
| LMArena Agent | – | 12 |
| LiveBench | 76.2% | 75.7% |
| LiveBench Reasoning | 89.2% | 91.6% |
| LiveBench Coding | 81.8% | 91.4% |
| LiveBench Agentic Coding | 50.5% | 56.3% |
| LiveBench Mathematics | 94.3% | 96.1% |
| LiveBench Data Analysis | 66.0% | 59.5% |
| LiveBench Language | 79.7% | 78.0% |
| LiveBench Instruction Following | 72.0% | 56.8% |
| AA Intelligence Index v4.3.2 | 41.8 | 56 |
| IFBench | 62.2% | – |
| AA-LCR | 77.7% | 82.7% |
| AA-Omniscience | 28.8 | 32.3 |
| Terminal-Bench Hard | 58.3% | – |
| GPQA Diamond (AA) | 92.0% | – |
| Humanity's Last Exam (AA) | 48.7% | 55.0% |
| SciCode (AA) | 54.4% | 61.0% |
| τ²-Bench Telecom (AA) | 94.4% | – |
| AIME 2026 | 100.0% | – |
| HMMT February 2026 | 95.5% | – |
| MathArena Apex | 81.3% | – |
| MCP Atlas | 82.2% | – |
| ARC-AGI-1 | 92.5% | – |
| CritPt | 20.9% | 31.4% |
| GDPval-AA v2.1 | 47.8% | 67.0% |
| τ³-Banking (AA) | 34.2% | – |
| Analyst Agent (AA) | 45.0% | 57.5% |
| FORTRESS | 18.2% | – |
| Chess Puzzles | 34.0% | – |
| EBR-bench | 28.6% | – |
| Mystery Game Puzzles | 36.0% | 65.0% |
| PostTrainBench | 32.9% | – |
| DeepSWE v1.1 | 59.0% | – |
| LMCA | 57.5% | – |
| DTBench | 94.9% | – |
| CursorBench | – | 55.5% |
| Vending-Bench 2 | 2992.3 | – |
| GDP.pdf | 24.0% | – |
| FrontierSWE | – | 61.9% |
| Terminal-Bench 4.0 (AA) | 21.7% | 63.6% |
| Terminal-Bench 2.1 (AA) | 84.6% | – |
| AutomationBench | – | 71.8% |
| GDP.pdf | – | 25.8% |
| MLCR | – | 75.0% |
| Harvey LAB | – | 2.8% |
| AA-Omniscience: accuracy | 48.8% | 54.0% |
| AA-Omniscience: non-hallucination | 60.8% | 53.0% |
| AA-Briefcase v1.1 | – | 1823 |
Data as of 2026-10-11. Best configuration of each model; every score links to its source on the model pages.
Claude Opus 4.8 vs Claude Sonnet 5.5: questions
- Is Claude Opus 4.8 better than Claude Sonnet 5.5?
- Claude Sonnet 5.5 (max) leads on quality: 67.6 vs 62.4. The BenchLeader Index combines every independent quality benchmark; Claude Sonnet 5.5 (max) is ahead overall as of 2026-10-11, but check the category scores for your use.
- Is Claude Opus 4.8 better than Claude Sonnet 5.5 for coding?
- Claude Sonnet 5.5 scores higher in coding (70 vs 60 on the category index, where 50 is average).
- Is Claude Opus 4.8 better than Claude Sonnet 5.5 for agentic tasks?
- Claude Sonnet 5.5 scores higher in agentic tasks (70 vs 57 on the category index, where 50 is average).
- Which is cheaper, Claude Opus 4.8 or Claude Sonnet 5.5?
- Claude Sonnet 5.5 is cheaper: $4.00 against $10.00 per million tokens, blended at three input tokens per output token.
- Which is faster, Claude Opus 4.8 or Claude Sonnet 5.5?
- Claude Sonnet 5.5 streams faster: 141 against 58 output tokens per second.
- Which has the larger context window?
- Both accept 1M tokens of context.