# Claude Opus 4.5 vs Claude Sonnet 5.5

> Side-by-side benchmark comparison for Claude Opus 4.5 and Claude Sonnet 5.5 across agentic, coding, multimodal, knowledge, reasoning, multilingual, and math tasks.

- Canonical page: https://benchlm.ai/compare/claude-opus-4-5-vs-claude-sonnet-5-5
- Last updated: September 28, 2026

- Shared sourced benchmarks: 2
- HTML indexing: indexable
- Ranking lane: BenchAlign v5.7

## Quick Verdict

Evidence is too thin for a benchmark verdict: Claude Opus 4.5 and Claude Sonnet 5.5 share only 2 sourced benchmark rows.

## Summary

- Only 2 shared sourced benchmark rows are available. That is not enough for a broad capability verdict, so this mirror does not name an overall winner.
- Claude Sonnet 5.5 has the lower published output-token price.
- Claude Sonnet 5.5 has the larger published context window at 1M.

## Model Snapshot

| Property | Claude Opus 4.5 | Claude Sonnet 5.5 |
|----------|----------|----------|
| Creator | Anthropic | Anthropic |
| Type | Proprietary | Proprietary |
| Reasoning | Non-Reasoning | Reasoning |
| Context | 200K | 1M |
| Independent public score (not head-to-head) | 55.03 | 80.49 |
| Benchmarks Covered | 45 | 47 |
| Pricing (input/output) | $5.00 / $25.00 | $2.00 / $10.00 |

## Category Breakdown

### Agentic

- Winner: Insufficient shared evidence
- Claude Opus 4.5 public-lane score: 30.8 (Estimated · #72/111)
- Claude Sonnet 5.5 public-lane score: 66.1 (Supported · #10/111)

| Benchmark | Claude Opus 4.5 | Claude Sonnet 5.5 | Winner |
|-----------|-----------|-----------|--------|
| Terminal-Bench 2.0 | 59.3% | Coming soon | Coming soon |
| OSWorld-Verified | 66.3% | Coming soon | Coming soon |
| OSWorld | 66.3% | Coming soon | Coming soon |
| Claw-Eval | 59.6% | Coming soon | Coming soon |
| QwenClawBench | 52.3% | Coming soon | Coming soon |
| τ³-bench results | 70.2% | Coming soon | Coming soon |
| VITA-Bench | 23.3% | Coming soon | Coming soon |
| DeepPlanning | 26.4% | Coming soon | Coming soon |
| Toolathlon | 43.5% | Coming soon | Coming soon |
| MCP Atlas | 42.3% | Coming soon | Coming soon |
| MCP-Tasks | 71.8% | Coming soon | Coming soon |
| WideResearch | 76.4% | Coming soon | Coming soon |
| CyberGym | 50.6% | Coming soon | Coming soon |
| Gert Labs | 64.23% | Coming soon | Coming soon |
| JobBench | 32.3% | Coming soon | Coming soon |
| Terminal-Bench 4.0 | Coming soon | 70.60% | Coming soon |
| HLE w/ tools | Coming soon | 64.5% | Coming soon |
| DRACO | Coming soon | 87.0% | Coming soon |
| Terminal-Bench-Science 0.1 | Coming soon | 59.9% | Coming soon |
| LAB all-pass (Harvey held-out) | Coming soon | 10.0% | Coming soon |
| LAB criterion-pass (Harvey held-out) | Coming soon | 93.1% | Coming soon |
| Toolathlon Verified Pass@3 | Coming soon | 85.2% | Coming soon |
| Toolathlon Verified Pass³ | Coming soon | 68.5% | Coming soon |
| Toolathlon Verified avg. turns | Coming soon | 31.6 turns | Coming soon |
| AutomationBench (Zapier 1.0.6) | Coming soon | 44.7% | Coming soon |
| Toolathlon-Verified | Coming soon | 77.8% | Coming soon |

### Coding

- Winner: Insufficient shared evidence
- Claude Opus 4.5 public-lane score: 42.1 (Estimated · #53/136)
- Claude Sonnet 5.5 public-lane score: 79.6 (Estimated · #3/136)

| Benchmark | Claude Opus 4.5 | Claude Sonnet 5.5 | Winner |
|-----------|-----------|-----------|--------|
| SWE-bench Verified | 80.9% | Coming soon | Coming soon |
| LiveCodeBench v6 | 84.8% | Coming soon | Coming soon |
| SWE-bench Pro | 57.1% | 81.3% | Claude Sonnet 5.5 |
| SWE Multilingual | 77.5% | 90.3% | Claude Sonnet 5.5 |
| NL2Repo | 43.2% | Coming soon | Coming soon |
| FrontierCode 1.1 Main | Coming soon | 46.2% | Coming soon |
| cursorBench40 | Coming soon | 55.5% | Coming soon |
| SWE Multimodal | Coming soon | 54.3% | Coming soon |
| DeepSWE | Coming soon | 71.0% | Coming soon |
| FrontierCode 1.1 Extended | Coming soon | 59.1% | Coming soon |
| ProgramBench | Coming soon | 79.7% | Coming soon |
| FrontierSWE v2 | Coming soon | 61.9% | Coming soon |

### Reasoning

- Winner: Insufficient shared evidence
- Claude Opus 4.5 public-lane score: 73.3 (Unranked · 4 rankable rows)
- Claude Sonnet 5.5 public-lane score: 79.2 (#7/27)

| Benchmark | Claude Opus 4.5 | Claude Sonnet 5.5 | Winner |
|-----------|-----------|-----------|--------|
| LongBench v2 | 64.4% | Coming soon | Coming soon |
| AI-Needle | 74% | Coming soon | Coming soon |

### Multimodal & Grounded

- Winner: Insufficient shared evidence
- Claude Opus 4.5 public-lane score: 24.5 (#48/50)
- Claude Sonnet 5.5 public-lane score: 83.3 (Unranked · 7 rankable rows)

| Benchmark | Claude Opus 4.5 | Claude Sonnet 5.5 | Winner |
|-----------|-----------|-----------|--------|
| MMMU-Pro | 70.6% | Coming soon | Coming soon |
| MathVision | 74.3% | Coming soon | Coming soon |
| CharXiv | 68.5% | Coming soon | Coming soon |
| VideoMMMU | 84.4% | Coming soon | Coming soon |
| ScreenSpot Pro | 45.7% | Coming soon | Coming soon |
| V* | 67.0% | Coming soon | Coming soon |
| Chartography (no tools) | Coming soon | 61.6% | Coming soon |
| Chartography (tools) | Coming soon | 90.2% | Coming soon |
| BenchCAD Vision2Code (no tools) | Coming soon | 0.747 | Coming soon |
| BenchCAD Vision2Code (tools) | Coming soon | 0.963 | Coming soon |
| Biomedical image analysis | Coming soon | 72.2% | Coming soon |
| OfficeQA | Coming soon | 76.9% | Coming soon |
| OfficeQA Pro | Coming soon | 65.6% | Coming soon |

### Knowledge

- Winner: Insufficient shared evidence
- Claude Opus 4.5 public-lane score: 49.5 (Estimated · #57/160)
- Claude Sonnet 5.5 public-lane score: 80.9 (Supported · #6/160)

| Benchmark | Claude Opus 4.5 | Claude Sonnet 5.5 | Winner |
|-----------|-----------|-----------|--------|
| GPQA | 87% | Coming soon | Coming soon |
| SuperGPQA | 70.6% | Coming soon | Coming soon |
| MMLU-Pro | 89.5% | Coming soon | Coming soon |
| MMLU-Redux | 96.6% | Coming soon | Coming soon |
| C-Eval | 92.2% | Coming soon | Coming soon |
| HLE | 30.8% | Coming soon | Coming soon |
| HealthBench (raw) | Coming soon | 69.4% | Coming soon |
| HealthBench (length-adjusted) | Coming soon | 65.4% | Coming soon |
| HealthBench Professional (raw) | Coming soon | 77.1% | Coming soon |
| HealthBench Professional | Coming soon | 69.2% | Coming soon |
| BioMysteryBench (human-solvable) | Coming soon | 89.2% | Coming soon |
| BioMysteryBench (human-difficult) | Coming soon | 44.7% | Coming soon |
| SpatialBench Verified | Coming soon | 72.5% | Coming soon |
| SingleCellBench | Coming soon | 59.1% | Coming soon |
| Protein Design | Coming soon | 51.0% | Coming soon |
| Morphology-to-molecule matching | Coming soon | 25.0% | Coming soon |
| Medicinal chemistry | Coming soon | 65.3% | Coming soon |
| Protein Design library ranking | Coming soon | 54.8% | Coming soon |
| De novo protein-binder design | Coming soon | 82.3% | Coming soon |
| Protocols (troubleshooting) | Coming soon | 67.3% | Coming soon |
| Protocols (understanding) | Coming soon | 66.6% | Coming soon |
| HLE w/o tools | Coming soon | 56.9% | Coming soon |

### Multilingual

- Winner: Insufficient shared evidence
- Claude Opus 4.5 public-lane score: 82.9 (#2/12)
- Claude Sonnet 5.5 public-lane score: Coming soon

| Benchmark | Claude Opus 4.5 | Claude Sonnet 5.5 | Winner |
|-----------|-----------|-----------|--------|
| MMLU-ProX | 85.7% | Coming soon | Coming soon |
| NOVA-63 | 56.7% | Coming soon | Coming soon |
| GMMLU | Coming soon | 92.1% | Coming soon |
| MILU | Coming soon | 91.6% | Coming soon |

### Instruction Following

- Winner: Insufficient shared evidence
- Claude Opus 4.5 public-lane score: 30.6 (#114/124)
- Claude Sonnet 5.5 public-lane score: Coming soon

| Benchmark | Claude Opus 4.5 | Claude Sonnet 5.5 | Winner |
|-----------|-----------|-----------|--------|
| IFEval | 90.9% | Coming soon | Coming soon |
| IFBench | 58% | Coming soon | Coming soon |

### Mathematics

- Winner: Insufficient shared evidence
- Claude Opus 4.5 public-lane score: 57.9 (#6/7)
- Claude Sonnet 5.5 public-lane score: Coming soon

| Benchmark | Claude Opus 4.5 | Claude Sonnet 5.5 | Winner |
|-----------|-----------|-----------|--------|
| AIME26 | 95.1% | Coming soon | Coming soon |
| HMMT Feb 2025 | 92.9% | Coming soon | Coming soon |
| HMMT Nov 2025 | 93.3% | Coming soon | Coming soon |
| HMMT Feb 2026 | 85.3% | Coming soon | Coming soon |
| MMAnswerBench | 84.0% | Coming soon | Coming soon |
| FrontierMath v2 (Tiers 1-3) | 20.690% | Coming soon | Coming soon |
| FrontierMath v2 (Tier 4) | 4.167% | Coming soon | Coming soon |
| ArXivMath Aug. 2026 (no tools) | Coming soon | 86.8% | Coming soon |
| ArXivMath Aug. 2026 (tools) | Coming soon | 95.2% | Coming soon |

## FAQ

### Is there enough evidence to pick between Claude Opus 4.5 and Claude Sonnet 5.5?

Not yet. The models share only 2 sourced benchmark rows, so this mirror reports the available measurements and metadata without naming a broad winner.

### What can I compare safely on this page?

Published pricing, context windows, model type, and individual shared benchmark rows are directly comparable. Independent overall scores and non-overlapping benchmark coverage are labeled separately and should not be read as a controlled head-to-head result.

## Related Comparisons

- [Claude Opus 4.5 vs Claude Opus 4.5 Thinking](/compare/claude-opus-4-5-vs-claude-opus-4-5-thinking)
- [Claude Sonnet 5.5 vs Claude Opus 4.5 Thinking](/compare/claude-opus-4-5-thinking-vs-claude-sonnet-5-5)
- [Claude Opus 4.5 vs GPT-6 Astra](/compare/claude-opus-4-5-vs-gpt-6-astra)
- [Claude Sonnet 5.5 vs GPT-6 Astra](/compare/claude-sonnet-5-5-vs-gpt-6-astra)

## Explore More

- [Claude Opus 4.5 profile](/models/claude-opus-4-5)
- [Claude Sonnet 5.5 profile](/models/claude-sonnet-5-5)
- [Compare Pricing](/llm-pricing)
- [Alternative Finder](/tools/alternative-finder)
- [LLM Selector](/tools/llm-selector)
- [Overall Rankings](/best/overall)