# Claude Opus 5.5 vs Step 5 Preview

> Side-by-side benchmark comparison for Claude Opus 5.5 and Step 5 Preview across agentic, coding, multimodal, knowledge, reasoning, multilingual, and math tasks.

- Canonical page: https://benchlm.ai/compare/claude-opus-5-5-vs-step-5-preview
- 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. Step 5 Preview 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 72.
- The clearest category separation is in multimodal & grounded, where the averages are 88.8 for Claude Opus 5.5 and 61.2 for Step 5 Preview.
- The biggest single benchmark swing is Terminal-Bench 4.0 in Agentic, with scores of 66.40% and 33.30%.
- Step 5 Preview is the cheaper option on output tokens, which matters if you expect large responses or heavy interactive use.

## Model Snapshot

| Property | Claude Opus 5.5 | Step 5 Preview |
|----------|----------|----------|
| Creator | Anthropic | StepFun |
| Type | Proprietary | Pending |
| Reasoning | Reasoning | Reasoning |
| Context | 1M | 1M |
| Overall Score | 81.03 | null |
| Benchmarks Covered | 47 | 22 |
| Pricing (input/output) | $4.00 / $20.00 | $1.00 / $2.70 |

## Category Breakdown

### Agentic

- Winner: Coming soon
- Claude Opus 5.5 public-lane score: 82.9 (Supported · #1/157)
- Step 5 Preview public-lane score: Coming soon

| Benchmark | Claude Opus 5.5 | Step 5 Preview | Winner |
|-----------|-----------|-----------|--------|
| Terminal-Bench 4.0 | 66.40% | 33.30% | Claude Opus 5.5 |
| Terminal-Bench-Science 0.1 | 58.7% | Coming soon | Coming soon |
| AutomationBench | 40.0% | 44.0% | Step 5 Preview |
| HLE w/ tools | 67.7% | Coming soon | Coming soon |
| 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% | 74.1% | 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 | 85.0% | Coming soon |
| CyberGym | Coming soon | 84.7% | Coming soon |
| MCP Atlas | Coming soon | 85.6% | Coming soon |
| JobBench | Coming soon | 59.0% | Coming soon |
| APEX-Agents | Coming soon | 37.8% | Coming soon |
| DRACO | Coming soon | 83.3% | Coming soon |
| BrowseComp | Coming soon | 88.7% | Coming soon |
| Agents' Last Exam | Coming soon | 29.5% | Coming soon |

### Coding

- Winner: Coming soon
- Claude Opus 5.5 public-lane score: 80.1 (Supported · #2/159)
- Step 5 Preview public-lane score: Coming soon

| Benchmark | Claude Opus 5.5 | Step 5 Preview | Winner |
|-----------|-----------|-----------|--------|
| FrontierCode 1.1 Main | 54.4% | Coming soon | Coming soon |
| cursorBench40 | 57.8% | Coming soon | Coming soon |
| SWE-bench Pro | 89.9% | Coming soon | Coming soon |
| SWE Multilingual | 93.9% | Coming soon | Coming soon |
| SWE Multimodal | 61.4% | Coming soon | Coming soon |
| DeepSWE | 74.2% | 67.7% | 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% | 80.5% | Claude Opus 5.5 |
| Terminal-Bench 2.1 | Coming soon | 85.0% | Coming soon |
| SciCode | Coming soon | 58.9% | Coming soon |
| sweMarathon | Coming soon | 72.7% | Coming soon |
| MLS-Bench Lite | Coming soon | 40.5% | Coming soon |

### Reasoning

- Winner: Coming soon
- Claude Opus 5.5 public-lane score: 78.5 (#4/17)
- Step 5 Preview public-lane score: 78.5 (Unranked · 2 rankable rows)

| Benchmark | Claude Opus 5.5 | Step 5 Preview | Winner |
|-----------|-----------|-----------|--------|
| CritPt | Coming soon | 20.9% | Coming soon |

### Multimodal & Grounded

- Winner: Coming soon
- Claude Opus 5.5 public-lane score: 88.8 (#3/50)
- Step 5 Preview public-lane score: 61.2 (#29/50)

| Benchmark | Claude Opus 5.5 | Step 5 Preview | 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% | 60.3% | Claude Opus 5.5 |
| MMMU-Pro | Coming soon | 76% | Coming soon |

### Knowledge

- Winner: Coming soon
- Claude Opus 5.5 public-lane score: 81.8 (Estimated · #4/189)
- Step 5 Preview public-lane score: Coming soon

| Benchmark | Claude Opus 5.5 | Step 5 Preview | Winner |
|-----------|-----------|-----------|--------|
| HLE w/o tools | 64.4% | Coming soon | Coming soon |
| 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-D | Coming soon | 93.5% | Coming soon |
| HLE | Coming soon | 46.5% | Coming soon |

### Multilingual

- Winner: Coming soon
- Claude Opus 5.5 public-lane score: Coming soon
- Step 5 Preview public-lane score: Coming soon

| Benchmark | Claude Opus 5.5 | Step 5 Preview | 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
- Step 5 Preview public-lane score: Coming soon

| Benchmark | Claude Opus 5.5 | Step 5 Preview | 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 Step 5 Preview?

Claude Opus 5.5 is ahead overall on BenchLM right now.

### Where is the biggest gap between Claude Opus 5.5 and Step 5 Preview?

The widest category gap is in multimodal & grounded, where the averages are 88.8 for Claude Opus 5.5 and 61.2 for Step 5 Preview.

### 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 Step 5 Preview cover on BenchLM?

Step 5 Preview currently has 22 sourced benchmark scores on BenchLM.

## Related Comparisons

- [Claude Opus 5.5 vs Claude Fable 5.1](/compare/claude-fable-5-1-vs-claude-opus-5-5)
- [Step 5 Preview vs Claude Fable 5.1](/compare/claude-fable-5-1-vs-step-5-preview)
- [Claude Opus 5.5 vs GPT-6 Astra](/compare/claude-opus-5-5-vs-gpt-6-astra)
- [Step 5 Preview vs GPT-6 Astra](/compare/gpt-6-astra-vs-step-5-preview)

## Explore More

- [Claude Opus 5.5 profile](/models/claude-opus-5-5)
- [Step 5 Preview profile](/models/step-5-preview)
- [Compare Pricing](/llm-pricing)
- [Alternative Finder](/tools/alternative-finder)
- [LLM Selector](/tools/llm-selector)
- [Overall Rankings](/best/overall)