# Particle-1 vs Step 5 Preview

> Side-by-side benchmark comparison for Particle-1 and Step 5 Preview across agentic, coding, multimodal, knowledge, reasoning, multilingual, and math tasks.

- Canonical page: https://benchlm.ai/compare/particle-1-vs-step-5-preview
- Last updated: October 29, 2026

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

## Quick Verdict

Step 5 Preview leads by point estimate. Conditional score ranges do not establish rank confidence. Choose using the category evidence and your own workload tests.

## Summary

- Step 5 Preview has the higher overall point estimate 56.15 to 0. Conditional score ranges do not establish rank confidence.
- The biggest single benchmark swing is Terminal-Bench 2.1 in Agentic, with scores of 79.9% and 85.0%.
- Particle-1 is the cheaper option on output tokens, which matters if you expect large responses or heavy interactive use.

## Model Snapshot

| Property | Particle-1 | Step 5 Preview |
|----------|----------|----------|
| Creator | Particle AI | StepFun |
| Type | Proprietary | Open Weight |
| Reasoning | Reasoning | Reasoning |
| Context | 1M | 1M |
| Overall Score | null | 56.15 |
| Benchmarks Covered | 5 | 24 |
| Pricing (input/output) | $0.25 / $1.00 | $1.00 / $2.70 |

## Category Breakdown

### Agentic

- Winner: Not comparable
- Particle-1 public-lane score: Coming soon
- Step 5 Preview public-lane score: 54.7 (Estimated · #42/135)

| Benchmark | Particle-1 | Step 5 Preview | Winner |
|-----------|-----------|-----------|--------|
| Terminal-Bench 2.1 | 79.9% | 85.0% | Step 5 Preview |
| Terminal-Bench 4.0 | Coming soon | 33.30% | Coming soon |
| CyberGym | Coming soon | 84.7% | Coming soon |
| AutomationBench | Coming soon | 44.0% | Coming soon |
| Toolathlon-Verified | Coming soon | 74.1% | 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 |
| Hermes Index | Coming soon | 32.8% | Coming soon |
| Hermes Bench | Coming soon | 69.2% | Coming soon |

### Coding

- Winner: Not comparable
- Particle-1 public-lane score: Coming soon
- Step 5 Preview public-lane score: 48.3 (Estimated · #48/156)

| Benchmark | Particle-1 | Step 5 Preview | Winner |
|-----------|-----------|-----------|--------|
| Terminal-Bench 2.1 | 79.9% | 85.0% | Step 5 Preview |
| DeepSWE | 72.6% | 67.7% | Particle-1 |
| SciCode | Coming soon | 58.9% | Coming soon |
| ProgramBench | Coming soon | 80.5% | Coming soon |
| sweMarathon | Coming soon | 72.7% | Coming soon |
| MLS-Bench Lite | Coming soon | 40.5% | Coming soon |

### Reasoning

- Winner: Not comparable
- Particle-1 public-lane score: Coming soon
- Step 5 Preview public-lane score: 82.5 (Unranked · 2 rankable rows)

| Benchmark | Particle-1 | Step 5 Preview | Winner |
|-----------|-----------|-----------|--------|
| CritPt | Coming soon | 20.9% | Coming soon |

### Multimodal & Grounded

- Winner: Not comparable
- Particle-1 public-lane score: Coming soon
- Step 5 Preview public-lane score: 73.3 (#32/58)

| Benchmark | Particle-1 | Step 5 Preview | Winner |
|-----------|-----------|-----------|--------|
| OfficeQA Pro | Coming soon | 60.3% | Coming soon |
| MMMU-Pro | Coming soon | 76% | Coming soon |

### Knowledge

- Winner: Not comparable
- Particle-1 public-lane score: Coming soon
- Step 5 Preview public-lane score: 59.9 (Supported · #46/179)

| Benchmark | Particle-1 | Step 5 Preview | Winner |
|-----------|-----------|-----------|--------|
| GPQA-D | 90.4% | 93.5% | Step 5 Preview |
| MMLU | 86.1% | Coming soon | Coming soon |
| HLE | Coming soon | 46.5% | Coming soon |

## FAQ

### Which is better overall, Particle-1 or Step 5 Preview?

Step 5 Preview has the higher overall point estimate. Conditional score ranges do not establish rank confidence.

### How many benchmarks does Particle-1 cover on BenchLM?

Particle-1 currently has 5 sourced benchmark scores on BenchLM.

### How many benchmarks does Step 5 Preview cover on BenchLM?

Step 5 Preview currently has 24 sourced benchmark scores on BenchLM.

## Related Comparisons

- [Particle-1 vs Gemini 4 Carbon](/compare/gemini-4-carbon-vs-particle-1)
- [Step 5 Preview vs Gemini 4 Carbon](/compare/gemini-4-carbon-vs-step-5-preview)
- [Particle-1 vs Claude Opus 5.5](/compare/claude-opus-5-5-vs-particle-1)
- [Step 5 Preview vs Claude Opus 5.5](/compare/claude-opus-5-5-vs-step-5-preview)

## Explore More

- [Particle-1 profile](/models/particle-1)
- [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)