# Claude 3.5 Sonnet vs Claude Opus 4.8

> Side-by-side benchmark comparison for Claude 3.5 Sonnet and Claude Opus 4.8 across agentic, coding, multimodal, knowledge, reasoning, multilingual, and math tasks.

- Canonical page: https://benchlm.ai/compare/claude-3-5-sonnet-vs-claude-opus-4-8
- Last updated: October 10, 2026

- Shared sourced benchmarks: 4
- HTML indexing: indexable
- Ranking lane: BenchAlign v5.8

## Quick Verdict

Claude Opus 4.8 leads by point estimate. Conditional score ranges do not establish rank confidence. Choose using the category evidence and your own workload tests.

## Summary

- Claude Opus 4.8 has the higher overall point estimate 69.12 to 28.27. Conditional score ranges do not establish rank confidence.
- The clearest category separation is in mathematics, where the averages are 26.1 for Claude 3.5 Sonnet and 65.7 for Claude Opus 4.8.
- The biggest single benchmark swing is FrontierMath v2 (Tiers 1-3) in Mathematics, with scores of 2.069% and 47.241%.
- Claude 3.5 Sonnet is the cheaper option on output tokens, which matters if you expect large responses or heavy interactive use.
- Claude Opus 4.8 also has the larger context window at 1M.

## Model Snapshot

| Property | Claude 3.5 Sonnet | Claude Opus 4.8 |
|----------|----------|----------|
| Creator | Anthropic | Anthropic |
| Type | Proprietary | Proprietary |
| Reasoning | Non-Reasoning | Reasoning |
| Context | 200K | 1M |
| Overall Score | 28.27 | 69.12 |
| Benchmarks Covered | 4 | 40 |
| Pricing (input/output) | $3.00 / $15.00 | $5.00 / $25.00 |

## Category Breakdown

### Agentic

- Winner: Not comparable
- Claude 3.5 Sonnet public-lane score: Coming soon
- Claude Opus 4.8 public-lane score: 61.6 (Supported · #20/123)

| Benchmark | Claude 3.5 Sonnet | Claude Opus 4.8 | Winner |
|-----------|-----------|-----------|--------|
| Terminal-Bench 3.0 | Coming soon | 21.1% | Coming soon |
| Terminal-Bench 2.1 | Coming soon | 74.6% | Coming soon |
| BrowseComp | Coming soon | 84.3% | Coming soon |
| DeepSearchQA | Coming soon | 93.1% | Coming soon |
| OSWorld-Verified | Coming soon | 83.4% | Coming soon |
| Finance Agent v2 | Coming soon | 53.9% | Coming soon |
| MCP Atlas | Coming soon | 82.2% | Coming soon |
| Toolathlon | Coming soon | 59.9% | Coming soon |
| Gert Labs | Coming soon | 72.97% | Coming soon |
| ResearchClawBench | Coming soon | 21.1% | Coming soon |
| OSWorld 2.0 | Coming soon | 20.6% | Coming soon |
| Terminal-Bench 2.1 (Vals) | Coming soon | 71.9% | Coming soon |

### Coding

- Winner: Not comparable
- Claude 3.5 Sonnet public-lane score: Coming soon
- Claude Opus 4.8 public-lane score: 60.8 (Supported · #19/146)

| Benchmark | Claude 3.5 Sonnet | Claude Opus 4.8 | Winner |
|-----------|-----------|-----------|--------|
| SWE-bench Verified | 49% | 88.6% | Claude Opus 4.8 |
| SWE-bench Pro | Coming soon | 69.2% | Coming soon |
| SWE Multilingual | Coming soon | 84.4% | Coming soon |
| SWE Multimodal | Coming soon | 38.4% | Coming soon |
| Terminal-Bench 2.1 | Coming soon | 74.6% | Coming soon |
| cursorBench31 | Coming soon | 58.4% | Coming soon |
| CursorBench 3.2 | Coming soon | 62.3% | Coming soon |
| FrontierCode 1.1 Main | Coming soon | 46.5% | Coming soon |
| LiveCodeBench (Vals) | Coming soon | 87.8% | Coming soon |
| SWE-bench (Vals) | Coming soon | 88.6% | Coming soon |
| PostTrainBench v1.1 | Coming soon | 32.9% | Coming soon |

### Reasoning

- Winner: Not comparable
- Claude 3.5 Sonnet public-lane score: Coming soon
- Claude Opus 4.8 public-lane score: 62.9 (#24/28)

| Benchmark | Claude 3.5 Sonnet | Claude Opus 4.8 | Winner |
|-----------|-----------|-----------|--------|
| ARC-AGI-2 | Coming soon | 72.1% | Coming soon |
| ARC-AGI-3 | Coming soon | 1.5% | Coming soon |
| ARC-AGI-1 | Coming soon | 92.50% | Coming soon |

### Multimodal & Grounded

- Winner: Not comparable
- Claude 3.5 Sonnet public-lane score: Coming soon
- Claude Opus 4.8 public-lane score: 91.2 (#5/54)

| Benchmark | Claude 3.5 Sonnet | Claude Opus 4.8 | Winner |
|-----------|-----------|-----------|--------|
| OfficeQA Pro | Coming soon | 66.2% | Coming soon |
| ScreenSpot Pro | Coming soon | 87.9% | Coming soon |
| CharXiv | Coming soon | 89.9% | Coming soon |
| CharXiv w/o tools | Coming soon | 80.5% | Coming soon |

### Knowledge

- Winner: Not comparable
- Claude 3.5 Sonnet public-lane score: Coming soon
- Claude Opus 4.8 public-lane score: 70.7 (Supported · #14/177)

| Benchmark | Claude 3.5 Sonnet | Claude Opus 4.8 | Winner |
|-----------|-----------|-----------|--------|
| GPQA | 59.4% | 93.6% | Claude Opus 4.8 |
| GPQA-D | Coming soon | 93.6% | Coming soon |
| HLE | Coming soon | 57.9% | Coming soon |
| HLE w/o tools | Coming soon | 49.8% | Coming soon |
| GPQA Diamond (Vals) | Coming soon | 92.4% | Coming soon |
| MMLU-Pro (Vals) | Coming soon | 89.6% | Coming soon |

### Multilingual

- Winner: Not comparable
- Claude 3.5 Sonnet public-lane score: Coming soon
- Claude Opus 4.8 public-lane score: Coming soon

| Benchmark | Claude 3.5 Sonnet | Claude Opus 4.8 | Winner |
|-----------|-----------|-----------|--------|
| INCLUDE | Coming soon | 87.6% | Coming soon |

### Instruction Following

- Winner: Not comparable
- Claude 3.5 Sonnet public-lane score: Coming soon
- Claude Opus 4.8 public-lane score: 75.4 (#61/127)

### Mathematics

- Winner: Not comparable
- Claude 3.5 Sonnet public-lane score: 26.1 (Unranked · 2 rankable rows)
- Claude Opus 4.8 public-lane score: 65.7 (#2/7)

| Benchmark | Claude 3.5 Sonnet | Claude Opus 4.8 | Winner |
|-----------|-----------|-----------|--------|
| FrontierMath v2 (Tiers 1-3) | 2.069% | 47.241% | Claude Opus 4.8 |
| FrontierMath v2 (Tier 4) | 0.000% | 31.250% | Claude Opus 4.8 |
| USAMO 2026 | Coming soon | 96.7% | Coming soon |

## FAQ

### Which is better overall, Claude 3.5 Sonnet or Claude Opus 4.8?

Claude Opus 4.8 has the higher overall point estimate. Conditional score ranges do not establish rank confidence.

### Where is the biggest gap between Claude 3.5 Sonnet and Claude Opus 4.8?

The widest category gap is in mathematics, where the averages are 26.1 for Claude 3.5 Sonnet and 65.7 for Claude Opus 4.8.

### How many benchmarks does Claude 3.5 Sonnet cover on BenchLM?

Claude 3.5 Sonnet currently has 4 sourced benchmark scores on BenchLM.

### How many benchmarks does Claude Opus 4.8 cover on BenchLM?

Claude Opus 4.8 currently has 40 sourced benchmark scores on BenchLM.

## Related Comparisons

- [Claude 3.5 Sonnet vs Claude Opus 5.5](/compare/claude-3-5-sonnet-vs-claude-opus-5-5)
- [Claude Opus 4.8 vs Claude Opus 5.5](/compare/claude-opus-4-8-vs-claude-opus-5-5)
- [Claude 3.5 Sonnet vs GPT-6 Astra](/compare/claude-3-5-sonnet-vs-gpt-6-astra)
- [Claude Opus 4.8 vs GPT-6 Astra](/compare/claude-opus-4-8-vs-gpt-6-astra)

## Explore More

- [Claude 3.5 Sonnet profile](/models/claude-3-5-sonnet)
- [Claude Opus 4.8 profile](/models/claude-opus-4-8)
- [Compare Pricing](/llm-pricing)
- [Alternative Finder](/tools/alternative-finder)
- [LLM Selector](/tools/llm-selector)
- [Overall Rankings](/best/overall)