# Claude Sonnet 5.5 vs Hy4 preview

> Side-by-side benchmark comparison for Claude Sonnet 5.5 and Hy4 preview across agentic, coding, multimodal, knowledge, reasoning, multilingual, and math tasks.

- Canonical page: https://benchlm.ai/compare/claude-sonnet-5-5-vs-hy4-preview
- Last updated: September 28, 2026

- Shared sourced benchmarks: 9
- HTML indexing: indexable
- Ranking lane: BenchAlign v5.7

## Quick Verdict

Pick Claude Sonnet 5.5 if you want the stronger benchmark profile. Hy4 preview only makes more sense when its price, context window, or workload-specific category wins matter more than the overall score.

## Summary

- Claude Sonnet 5.5 leads overall 80.49 to 60.26.
- The clearest category separation is in coding, where the averages are 79.6 for Claude Sonnet 5.5 and 60.4 for Hy4 preview.
- The biggest single benchmark swing is ProgramBench in Coding, with scores of 79.7% and 17.5%.
- Hy4 preview is the cheaper option on output tokens, which matters if you expect large responses or heavy interactive use.

## Model Snapshot

| Property | Claude Sonnet 5.5 | Hy4 preview |
|----------|----------|----------|
| Creator | Anthropic | Tencent |
| Type | Proprietary | Open Weight |
| Reasoning | Reasoning | Reasoning |
| Context | 1M | 1M |
| Overall Score | 80.49 | 60.26 |
| Benchmarks Covered | 47 | 29 |
| Pricing (input/output) | $2.00 / $10.00 | $0.00 / $0.00 |

## Category Breakdown

### Agentic

- Winner: Directional only
- Claude Sonnet 5.5 public-lane score: 66.1 (Supported · #10/111)
- Hy4 preview public-lane score: 52.9 (Estimated · #34/111)

| Benchmark | Claude Sonnet 5.5 | Hy4 preview | Winner |
|-----------|-----------|-----------|--------|
| Terminal-Bench 4.0 | 70.60% | Coming soon | Coming soon |
| HLE w/ tools | 64.5% | 55.4% | Claude Sonnet 5.5 |
| DRACO | 87.0% | 77.2% | Claude Sonnet 5.5 |
| Terminal-Bench-Science 0.1 | 59.9% | Coming soon | Coming soon |
| LAB all-pass (Harvey held-out) | 10.0% | Coming soon | Coming soon |
| LAB criterion-pass (Harvey held-out) | 93.1% | Coming soon | Coming soon |
| Toolathlon Verified Pass@3 | 85.2% | Coming soon | Coming soon |
| Toolathlon Verified Pass³ | 68.5% | Coming soon | Coming soon |
| Toolathlon Verified avg. turns | 31.6 turns | Coming soon | Coming soon |
| AutomationBench (Zapier 1.0.6) | 44.7% | Coming soon | Coming soon |
| Toolathlon-Verified | 77.8% | 74.1% | Claude Sonnet 5.5 |
| Terminal-Bench 2.1 | Coming soon | 85.4% | Coming soon |
| CyberGym | Coming soon | 78.4% | Coming soon |
| WideResearch | Coming soon | 83.9% | Coming soon |
| MCP Atlas | Coming soon | 83.7% | Coming soon |
| APEX-Agents | Coming soon | 37.1% | Coming soon |
| skillsBench | Coming soon | 62.9% | Coming soon |
| JobBench | Coming soon | 61.7% | Coming soon |
| Agents' Last Exam | Coming soon | 22.8% | Coming soon |
| AutomationBench | Coming soon | 32.1% | Coming soon |
| BankerToolBench | Coming soon | 78.6% | Coming soon |
| Terminal-Bench 2.1 (Vals) | Coming soon | 55.1% | Coming soon |

### Coding

- Winner: Directional only
- Claude Sonnet 5.5 public-lane score: 79.6 (Estimated · #3/136)
- Hy4 preview public-lane score: 60.4 (Supported · #16/136)

| Benchmark | Claude Sonnet 5.5 | Hy4 preview | Winner |
|-----------|-----------|-----------|--------|
| FrontierCode 1.1 Main | 46.2% | Coming soon | Coming soon |
| cursorBench40 | 55.5% | Coming soon | Coming soon |
| SWE-bench Pro | 81.3% | 65.7% | Claude Sonnet 5.5 |
| SWE Multilingual | 90.3% | 82.9% | Claude Sonnet 5.5 |
| SWE Multimodal | 54.3% | Coming soon | Coming soon |
| DeepSWE | 71.0% | 64.3% | Claude Sonnet 5.5 |
| FrontierCode 1.1 Extended | 59.1% | Coming soon | Coming soon |
| ProgramBench | 79.7% | 17.5% | Claude Sonnet 5.5 |
| FrontierSWE v2 | 61.9% | Coming soon | Coming soon |
| Terminal-Bench 2.1 | Coming soon | 85.4% | Coming soon |
| NL2Repo | Coming soon | 58.9% | Coming soon |
| PostTrain Bench | Coming soon | 35.6% | Coming soon |
| sweMarathon | Coming soon | 31.9% | Coming soon |

### Reasoning

- Winner: Not comparable
- Claude Sonnet 5.5 public-lane score: 79.2 (#7/27)
- Hy4 preview public-lane score: Coming soon

| Benchmark | Claude Sonnet 5.5 | Hy4 preview | Winner |
|-----------|-----------|-----------|--------|
| CritPt | Coming soon | 16.9% | Coming soon |

### Multimodal & Grounded

- Winner: Not comparable
- Claude Sonnet 5.5 public-lane score: 83.3 (Unranked · 7 rankable rows)
- Hy4 preview public-lane score: 84.9 (Unranked · 1 rankable row)

| Benchmark | Claude Sonnet 5.5 | Hy4 preview | Winner |
|-----------|-----------|-----------|--------|
| Chartography (no tools) | 61.6% | Coming soon | Coming soon |
| Chartography (tools) | 90.2% | Coming soon | Coming soon |
| BenchCAD Vision2Code (no tools) | 0.747 | Coming soon | Coming soon |
| BenchCAD Vision2Code (tools) | 0.963 | Coming soon | Coming soon |
| Biomedical image analysis | 72.2% | Coming soon | Coming soon |
| OfficeQA | 76.9% | Coming soon | Coming soon |
| OfficeQA Pro | 65.6% | 66.2% | Hy4 preview |

### Knowledge

- Winner: Directional only
- Claude Sonnet 5.5 public-lane score: 80.9 (Supported · #6/160)
- Hy4 preview public-lane score: 62.4 (Estimated · #32/160)

| Benchmark | Claude Sonnet 5.5 | Hy4 preview | Winner |
|-----------|-----------|-----------|--------|
| HealthBench (raw) | 69.4% | Coming soon | Coming soon |
| HealthBench (length-adjusted) | 65.4% | Coming soon | Coming soon |
| HealthBench Professional (raw) | 77.1% | Coming soon | Coming soon |
| HealthBench Professional | 69.2% | Coming soon | Coming soon |
| BioMysteryBench (human-solvable) | 89.2% | Coming soon | Coming soon |
| BioMysteryBench (human-difficult) | 44.7% | Coming soon | Coming soon |
| SpatialBench Verified | 72.5% | Coming soon | Coming soon |
| SingleCellBench | 59.1% | Coming soon | Coming soon |
| Protein Design | 51.0% | Coming soon | Coming soon |
| Morphology-to-molecule matching | 25.0% | Coming soon | Coming soon |
| Medicinal chemistry | 65.3% | Coming soon | Coming soon |
| Protein Design library ranking | 54.8% | Coming soon | Coming soon |
| De novo protein-binder design | 82.3% | Coming soon | Coming soon |
| Protocols (troubleshooting) | 67.3% | Coming soon | Coming soon |
| Protocols (understanding) | 66.6% | Coming soon | Coming soon |
| HLE w/o tools | 56.9% | 43.4% | Claude Sonnet 5.5 |
| GPQA | Coming soon | 92.3% | Coming soon |
| GPQA-D | Coming soon | 92.3% | Coming soon |
| HLE | Coming soon | 55.4% | Coming soon |

### Multilingual

- Winner: Not comparable
- Claude Sonnet 5.5 public-lane score: Coming soon
- Hy4 preview public-lane score: Coming soon

| Benchmark | Claude Sonnet 5.5 | Hy4 preview | Winner |
|-----------|-----------|-----------|--------|
| GMMLU | 92.1% | Coming soon | Coming soon |
| MILU | 91.6% | Coming soon | Coming soon |

### Mathematics

- Winner: Not comparable
- Claude Sonnet 5.5 public-lane score: Coming soon
- Hy4 preview public-lane score: Coming soon

| Benchmark | Claude Sonnet 5.5 | Hy4 preview | Winner |
|-----------|-----------|-----------|--------|
| ArXivMath Aug. 2026 (no tools) | 86.8% | Coming soon | Coming soon |
| ArXivMath Aug. 2026 (tools) | 95.2% | Coming soon | Coming soon |
| Apex | Coming soon | 74.2% | Coming soon |

## FAQ

### Which is better overall, Claude Sonnet 5.5 or Hy4 preview?

Claude Sonnet 5.5 is ahead overall on BenchLM right now.

### Where is the biggest gap between Claude Sonnet 5.5 and Hy4 preview?

The widest category gap is in coding, where the averages are 79.6 for Claude Sonnet 5.5 and 60.4 for Hy4 preview.

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

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

### How many benchmarks does Hy4 preview cover on BenchLM?

Hy4 preview currently has 29 sourced benchmark scores on BenchLM.

## Related Comparisons

- [Claude Sonnet 5.5 vs GPT-6 Astra](/compare/claude-sonnet-5-5-vs-gpt-6-astra)
- [Hy4 preview vs GPT-6 Astra](/compare/gpt-6-astra-vs-hy4-preview)
- [Claude Sonnet 5.5 vs Claude Opus 5.5](/compare/claude-opus-5-5-vs-claude-sonnet-5-5)
- [Hy4 preview vs Claude Opus 5.5](/compare/claude-opus-5-5-vs-hy4-preview)

## Explore More

- [Claude Sonnet 5.5 profile](/models/claude-sonnet-5-5)
- [Hy4 preview profile](/models/hy4-preview)
- [Compare Pricing](/llm-pricing)
- [Alternative Finder](/tools/alternative-finder)
- [LLM Selector](/tools/llm-selector)
- [Overall Rankings](/best/overall)