# Claude Sonnet 4.5 vs Step 3.7 Flash

> Side-by-side benchmark comparison for Claude Sonnet 4.5 and Step 3.7 Flash across agentic, coding, multimodal, knowledge, reasoning, multilingual, and math tasks.

- Canonical page: https://benchlm.ai/compare/claude-sonnet-4-5-vs-step-3-7-flash
- Last updated: October 15, 2026

- Shared sourced benchmarks: 1
- HTML indexing: indexable
- Ranking lane: BenchAlign v5.8

## Quick Verdict

Evidence is too thin for a benchmark verdict: Claude Sonnet 4.5 and Step 3.7 Flash share only 1 sourced benchmark row.

## Summary

- Only 1 shared sourced benchmark row is available. That is not enough for a broad capability verdict, so this mirror does not name an overall winner.
- Step 3.7 Flash has the lower published output-token price.
- Step 3.7 Flash has the larger published context window at 256K.

## Model Snapshot

| Property | Claude Sonnet 4.5 | Step 3.7 Flash |
|----------|----------|----------|
| Creator | Anthropic | StepFun |
| Type | Proprietary | Open Weight |
| Reasoning | Non-Reasoning | Reasoning |
| Context | 200K | 256K |
| Independent public score (not head-to-head) | 48.55 | 43.7 |
| Benchmarks Covered | 12 | 11 |
| Pricing (input/output) | $3.00 / $15.00 | $0.20 / $1.15 |

## Category Breakdown

### Agentic

- Winner: Insufficient shared evidence
- Claude Sonnet 4.5 public-lane score: 35.2 (Estimated · #80/126)
- Step 3.7 Flash public-lane score: 37.1 (Estimated · #74/126)

| Benchmark | Claude Sonnet 4.5 | Step 3.7 Flash | Winner |
|-----------|-----------|-----------|--------|
| Terminal-Bench 2.0 | 50% | Coming soon | Coming soon |
| OSWorld-Verified | 61.4% | Coming soon | Coming soon |
| VITA-Bench | 17.0% | Coming soon | Coming soon |
| Gert Labs | 48.51% | 51.57% | Step 3.7 Flash |
| JobBench | 27.7% | Coming soon | Coming soon |
| Terminal-Bench 2.1 | Coming soon | 59.5% | Coming soon |
| BrowseComp | Coming soon | 75.8% | Coming soon |
| DeepSearchQA | Coming soon | 92.8% | Coming soon |
| Toolathlon | Coming soon | 49.5% | Coming soon |
| Claw-Eval | Coming soon | 67.1% | Coming soon |
| HLE w/ tools | Coming soon | 47.2% | Coming soon |

### Coding

- Winner: Insufficient shared evidence
- Claude Sonnet 4.5 public-lane score: Coming soon
- Step 3.7 Flash public-lane score: 30.2 (Estimated · #95/149)

| Benchmark | Claude Sonnet 4.5 | Step 3.7 Flash | Winner |
|-----------|-----------|-----------|--------|
| SWE-bench Verified | 77.2% | Coming soon | Coming soon |
| Terminal-Bench 2.0 | 50.0% | Coming soon | Coming soon |
| SWE-bench Pro | Coming soon | 56.3% | Coming soon |
| Terminal-Bench 2.1 | Coming soon | 59.5% | Coming soon |

### Reasoning

- Winner: Insufficient shared evidence
- Claude Sonnet 4.5 public-lane score: 22.9 (Unranked · 1 rankable row)
- Step 3.7 Flash public-lane score: 76.5 (Unranked · 2 rankable rows)

| Benchmark | Claude Sonnet 4.5 | Step 3.7 Flash | Winner |
|-----------|-----------|-----------|--------|
| ARC-AGI-2 | 13.6% | Coming soon | Coming soon |

### Multimodal & Grounded

- Winner: Insufficient shared evidence
- Claude Sonnet 4.5 public-lane score: Coming soon
- Step 3.7 Flash public-lane score: 75.4 (Unranked · 3 rankable rows)

| Benchmark | Claude Sonnet 4.5 | Step 3.7 Flash | Winner |
|-----------|-----------|-----------|--------|
| SimpleVQA | Coming soon | 79.2% | Coming soon |
| V* | Coming soon | 95.3% | Coming soon |

### Knowledge

- Winner: Insufficient shared evidence
- Claude Sonnet 4.5 public-lane score: Coming soon
- Step 3.7 Flash public-lane score: 45 (Estimated · #96/182)

| Benchmark | Claude Sonnet 4.5 | Step 3.7 Flash | Winner |
|-----------|-----------|-----------|--------|
| GPQA | 83.4% | Coming soon | Coming soon |

### Instruction Following

- Winner: Insufficient shared evidence
- Claude Sonnet 4.5 public-lane score: Coming soon
- Step 3.7 Flash public-lane score: 82.1 (#54/146)

### Mathematics

- Winner: Insufficient shared evidence
- Claude Sonnet 4.5 public-lane score: 36.4 (Unranked · 2 rankable rows)
- Step 3.7 Flash public-lane score: Coming soon

| Benchmark | Claude Sonnet 4.5 | Step 3.7 Flash | Winner |
|-----------|-----------|-----------|--------|
| AIME 2025 | 87% | Coming soon | Coming soon |
| FrontierMath v2 (Tiers 1-3) | 23.860% | Coming soon | Coming soon |
| FrontierMath v2 (Tier 4) | 2.439% | Coming soon | Coming soon |

## FAQ

### Is there enough evidence to pick between Claude Sonnet 4.5 and Step 3.7 Flash?

Not yet. The models share only 1 sourced benchmark row, 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 Sonnet 4.5 vs Claude Sonnet 4.5 Thinking](/compare/claude-sonnet-4-5-vs-claude-sonnet-4-5-thinking)
- [Step 3.7 Flash vs Claude Sonnet 4.5 Thinking](/compare/claude-sonnet-4-5-thinking-vs-step-3-7-flash)
- [Claude Sonnet 4.5 vs Claude Opus 5.5](/compare/claude-opus-5-5-vs-claude-sonnet-4-5)
- [Step 3.7 Flash vs Claude Opus 5.5](/compare/claude-opus-5-5-vs-step-3-7-flash)

## Explore More

- [Claude Sonnet 4.5 profile](/models/claude-sonnet-4-5)
- [Step 3.7 Flash profile](/models/step-3-7-flash)
- [Compare Pricing](/llm-pricing)
- [Alternative Finder](/tools/alternative-finder)
- [LLM Selector](/tools/llm-selector)
- [Overall Rankings](/best/overall)