Claude Opus 4.8 vs Claude Sonnet 5
Claude Opus 4.8 Verdict
- Claude Opus 4.8 leads on quality: 64.8 vs 61.4.
- Claude Opus 4.8 is stronger in agents & tools, coding, composite, instruction following, knowledge, long context, multimodal.
- Claude Sonnet 5 (high) is stronger in human preference, reasoning.
- Claude Sonnet 5 (high) is 2.5× cheaper ($4.00 vs $10.00 per 1M blended).
| Metric | Claude Opus 4.8 | Claude Sonnet 5 (high) |
|---|---|---|
| BenchLeader Index | 64.8 | 61.4 |
| Agents & tools score | 65.0 | 61.8 |
| Coding score | 65.6 | 61.6 |
| Composite score | 82.1 | 69.5 |
| Human preference score | 65.8 | 66.2 |
| Instruction following score | 61.8 | – |
| Knowledge score | 66.5 | 62.4 |
| Long context score | 65.4 | 64.8 |
| Multimodal score | 64.5 | 63.1 |
| Reasoning score | 64.6 | 66.8 |
| Blended price $/M | $10.00 | $4.00 |
| Output speed | 56 tok/s | 60 tok/s |
| Time to first answer | 29.3 s | 10.0 s |
| Context window | 1M | 1M |
| SimpleBench | 64.8% | – |
| SciCode | – | 48.6% |
| Remote Labor Index | 8.3% | – |
| WeirdML | – | 68.8% |
| FrontierCode | 46.5% | – |
| GSO-Bench | 47.1% | – |
| Epoch Capabilities Index | 158.3 | – |
| LMArena Text | 1473 | 1462 |
| LMArena Hard Prompts | 1503 | 1490 |
| LMArena Coding | 1527 | 1521 |
| LMArena WebDev | 1540 | 1538 |
| LMArena Vision | 1289 | 1278 |
| LMArena Agent | – | 6.3 |
| AA Intelligence Index | 42.0 | 32.0 |
| IFBench | 62.2% | – |
| AA-LCR | 77.7% | 76.7% |
| AA-Omniscience | 28.8 | -3.7 |
| Terminal-Bench Hard | 58.3% | – |
| GPQA Diamond (AA) | 92.0% | – |
| Humanity's Last Exam (AA) | 48.7% | 35.7% |
| SciCode (AA) | 54.4% | 54.3% |
| τ²-Bench Telecom (AA) | 94.4% | – |
| LiveCodeBench | 87.8% | – |
| MMLU-Pro | 89.6% | – |
| LegalBench | 83.6% | – |
| CorpFin | 66.7% | – |
| TaxEval | 75.6% | – |
| Terminal-Bench 2.1 (Vals) | 71.9% | – |
| SWE-bench (Vals) | 88.6% | – |
| GPQA Diamond (Vals) | 92.4% | – |
| Vals Index | 60.9 | – |
| HiL-Bench | 35.3% | – |
| EQ-Bench 4 | 1281 | – |
Data as of 2026-09-10. Best configuration of each model; every score links to its source on the model pages.
Claude Opus 4.8 vs Claude Sonnet 5: questions
- Is Claude Opus 4.8 better than Claude Sonnet 5?
- Claude Opus 4.8 leads on quality: 64.8 vs 61.4. The BenchLeader Index combines every independent quality benchmark; Claude Opus 4.8 is ahead overall as of 2026-09-10, but check the category scores for your use.
- Is Claude Opus 4.8 better than Claude Sonnet 5 for coding?
- Claude Opus 4.8 scores higher in coding (66 vs 62 on the category index, where 50 is average).
- Is Claude Opus 4.8 better than Claude Sonnet 5 for agentic tasks?
- Claude Opus 4.8 scores higher in agentic tasks (65 vs 62 on the category index, where 50 is average).
- Which is cheaper, Claude Opus 4.8 or Claude Sonnet 5?
- Claude Sonnet 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?
- Claude Sonnet 5 streams faster: 60 against 56 output tokens per second.
- Which has the larger context window?
- Both accept 1M tokens of context.