# Claude Opus 5.5 vs Ornith-1.5-35B-A3B

> Side-by-side benchmark comparison for Claude Opus 5.5 and Ornith-1.5-35B-A3B across agentic, coding, multimodal, knowledge, reasoning, multilingual, and math tasks.

- Canonical page: https://benchlm.ai/compare/claude-opus-5-5-vs-ornith-1-5-35b-a3b
- Last updated: September 22, 2026

- Shared sourced benchmarks: 6
- HTML indexing: indexable
- Ranking lane: BenchAlign v5

## Quick Verdict

Pick Claude Opus 5.5 if you want the stronger benchmark profile. Ornith-1.5-35B-A3B only makes more sense when its price, context window, or workload-specific category wins matter more than the overall score.

## Summary

- Claude Opus 5.5 leads overall 81.03 to 34.14.
- The clearest category separation is in knowledge, where the averages are 81.8 for Claude Opus 5.5 and 40 for Ornith-1.5-35B-A3B.
- The biggest single benchmark swing is DeepSWE in Coding, with scores of 74.2% and 22.0%.
- Ornith-1.5-35B-A3B is the cheaper option on output tokens, which matters if you expect large responses or heavy interactive use.
- Claude Opus 5.5 also has the larger context window at 1M.

## Model Snapshot

| Property | Claude Opus 5.5 | Ornith-1.5-35B-A3B |
|----------|----------|----------|
| Creator | Anthropic | Ornith AI |
| Type | Proprietary | Open Weight |
| Reasoning | Reasoning | Reasoning |
| Context | 1M | 262K |
| Overall Score | 81.03 | 34.14 |
| Benchmarks Covered | 47 | 18 |
| Pricing (input/output) | $4.00 / $20.00 | $0.00 / $0.00 |

## Category Breakdown

### Agentic

- Winner: Coming soon
- Claude Opus 5.5 public-lane score: 82.9 (Supported · #1/157)
- Ornith-1.5-35B-A3B public-lane score: 47.5 (Estimated · #79/157)

| Benchmark | Claude Opus 5.5 | Ornith-1.5-35B-A3B | Winner |
|-----------|-----------|-----------|--------|
| Terminal-Bench 4.0 | 66.40% | Coming soon | Coming soon |
| Terminal-Bench-Science 0.1 | 58.7% | Coming soon | Coming soon |
| AutomationBench | 40.0% | Coming soon | Coming soon |
| HLE w/ tools | 67.7% | 33.4% | Claude Opus 5.5 |
| OSWorld 2.0 | 48.7% | Coming soon | Coming soon |
| LAB all-pass (Harvey held-out) | 8.3% | Coming soon | Coming soon |
| LAB criterion-pass (Harvey held-out) | 91.2% | Coming soon | Coming soon |
| Toolathlon-Verified | 77.8% | 48.7% | Claude Opus 5.5 |
| Toolathlon Verified Pass@3 | 82.4% | Coming soon | Coming soon |
| Toolathlon Verified Pass³ | 72.2% | Coming soon | Coming soon |
| Toolathlon Verified avg. turns | 26.9 turns | Coming soon | Coming soon |
| Terminal-Bench 2.1 | Coming soon | 67.8% | Coming soon |
| MCP Atlas | Coming soon | 70.2% | Coming soon |
| WideResearch | Coming soon | 67.8% | Coming soon |
| BrowseComp | Coming soon | 67.6% | Coming soon |
| Claw-Eval | Coming soon | 72.5% | Coming soon |

### Coding

- Winner: Coming soon
- Claude Opus 5.5 public-lane score: 80.1 (Supported · #2/159)
- Ornith-1.5-35B-A3B public-lane score: 47.4 (Estimated · #82/159)

| Benchmark | Claude Opus 5.5 | Ornith-1.5-35B-A3B | Winner |
|-----------|-----------|-----------|--------|
| FrontierCode 1.1 Main | 54.4% | Coming soon | Coming soon |
| cursorBench40 | 57.8% | Coming soon | Coming soon |
| SWE-bench Pro | 89.9% | 59.6% | Claude Opus 5.5 |
| SWE Multilingual | 93.9% | 71.4% | Claude Opus 5.5 |
| SWE Multimodal | 61.4% | Coming soon | Coming soon |
| DeepSWE | 74.2% | 22.0% | Claude Opus 5.5 |
| FrontierCode 1.1 Extended | 63.6% | Coming soon | Coming soon |
| FrontierSWE v2 | 62.3% | Coming soon | Coming soon |
| ProgramBench | 91.2% | Coming soon | Coming soon |
| Terminal-Bench 2.1 | Coming soon | 67.8% | Coming soon |
| SWE-bench Verified | Coming soon | 79% | Coming soon |
| frontierBench | Coming soon | 5.1% | Coming soon |
| NL2Repo | Coming soon | 46.2% | Coming soon |

### Reasoning

- Winner: Coming soon
- Claude Opus 5.5 public-lane score: 78.5 (#4/17)
- Ornith-1.5-35B-A3B public-lane score: Coming soon

### Multimodal & Grounded

- Winner: Coming soon
- Claude Opus 5.5 public-lane score: 88.8 (#3/50)
- Ornith-1.5-35B-A3B public-lane score: Coming soon

| Benchmark | Claude Opus 5.5 | Ornith-1.5-35B-A3B | Winner |
|-----------|-----------|-----------|--------|
| Chartography (tools) | 89.0% | Coming soon | Coming soon |
| Chartography (no tools) | 64.4% | Coming soon | Coming soon |
| BenchCAD Vision2Code (no tools) | 0.730 | Coming soon | Coming soon |
| BenchCAD Vision2Code (tools) | 0.962 | Coming soon | Coming soon |
| Biomedical image analysis | 71.4% | Coming soon | Coming soon |
| OfficeQA | 78.9% | Coming soon | Coming soon |
| OfficeQA Pro | 67.7% | Coming soon | Coming soon |

### Knowledge

- Winner: Coming soon
- Claude Opus 5.5 public-lane score: 81.8 (Estimated · #4/189)
- Ornith-1.5-35B-A3B public-lane score: 40 (Estimated · #138/189)

| Benchmark | Claude Opus 5.5 | Ornith-1.5-35B-A3B | Winner |
|-----------|-----------|-----------|--------|
| HLE w/o tools | 64.4% | 25.6% | Claude Opus 5.5 |
| HealthBench (raw) | 68.1% | Coming soon | Coming soon |
| HealthBench (length-adjusted) | 60.6% | Coming soon | Coming soon |
| HealthBench Professional | 65.6% | Coming soon | Coming soon |
| HealthBench Professional (raw) | 77.1% | Coming soon | Coming soon |
| BioMysteryBench (human-solvable) | 89.3% | Coming soon | Coming soon |
| BioMysteryBench (human-difficult) | 50.0% | Coming soon | Coming soon |
| SpatialBench Verified | 72.0% | Coming soon | Coming soon |
| SingleCellBench | 61.2% | Coming soon | Coming soon |
| Morphology-to-molecule matching | 34.0% | Coming soon | Coming soon |
| Medicinal chemistry | 63.5% | Coming soon | Coming soon |
| Protein Design | 60.2% | Coming soon | Coming soon |
| Protein Design library ranking | 56.0% | Coming soon | Coming soon |
| De novo protein-binder design | 82.6% | Coming soon | Coming soon |
| Protocols (troubleshooting) | 73.7% | Coming soon | Coming soon |
| Protocols (understanding) | 69.0% | Coming soon | Coming soon |
| GPQA | Coming soon | 89.2% | Coming soon |
| GPQA-D | Coming soon | 89.2% | Coming soon |
| HLE | Coming soon | 25.6% | Coming soon |

### Multilingual

- Winner: Coming soon
- Claude Opus 5.5 public-lane score: Coming soon
- Ornith-1.5-35B-A3B public-lane score: Coming soon

| Benchmark | Claude Opus 5.5 | Ornith-1.5-35B-A3B | Winner |
|-----------|-----------|-----------|--------|
| GMMLU | 94.3% | Coming soon | Coming soon |
| MILU | 93.1% | Coming soon | Coming soon |

### Mathematics

- Winner: Coming soon
- Claude Opus 5.5 public-lane score: Coming soon
- Ornith-1.5-35B-A3B public-lane score: Coming soon

| Benchmark | Claude Opus 5.5 | Ornith-1.5-35B-A3B | Winner |
|-----------|-----------|-----------|--------|
| ArXivMath Aug. 2026 (no tools) | 91.2% | Coming soon | Coming soon |
| ArXivMath Aug. 2026 (tools) | 96.9% | Coming soon | Coming soon |

## FAQ

### Which is better overall, Claude Opus 5.5 or Ornith-1.5-35B-A3B?

Claude Opus 5.5 is ahead overall on BenchLM right now.

### Where is the biggest gap between Claude Opus 5.5 and Ornith-1.5-35B-A3B?

The widest category gap is in knowledge, where the averages are 81.8 for Claude Opus 5.5 and 40 for Ornith-1.5-35B-A3B.

### How many benchmarks does Claude Opus 5.5 cover on BenchLM?

Claude Opus 5.5 currently has 47 sourced benchmark scores on BenchLM.

### How many benchmarks does Ornith-1.5-35B-A3B cover on BenchLM?

Ornith-1.5-35B-A3B currently has 18 sourced benchmark scores on BenchLM.

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## Explore More

- [Claude Opus 5.5 profile](/models/claude-opus-5-5)
- [Ornith-1.5-35B-A3B profile](/models/ornith-1-5-35b-a3b)
- [Compare Pricing](/llm-pricing)
- [Alternative Finder](/tools/alternative-finder)
- [LLM Selector](/tools/llm-selector)
- [Overall Rankings](/best/overall)