# Qwen3.5 Plus vs Step 3.5 Flash

> Qwen3.5 Plus and Step 3.5 Flash score almost the same on the Noometry Index (42.9 vs 42.3), so choose on price, context window or the category you care about most.

- Canonical page: https://noometry.com/compare/qwen3-5-plus-vs-step-3-5-flash
- Last updated: 2026-10-11
- Shared benchmarks: 0

## Summary

- The widest gap is in reasoning, where Qwen3.5 Plus leads 32.8 to 22.2.
- Step 3.5 Flash is cheaper at $0.10 / $0.30 per million input/output tokens, against $0.40 / $2.40 for Qwen3.5 Plus.
- Qwen3.5 Plus accepts more context: 1M tokens versus 256K.
- Step 3.5 Flash has downloadable open weights; the other is API-only.

## Snapshot

| | Qwen3.5 Plus | Step 3.5 Flash |
|---|---|---|
| Provider | Alibaba (Qwen) | StepFun |
| Noometry Index | 42.9 | 42.3 |
| Rank | 106 | 116 |
| Context | 1M | 256K |
| Input $/M | $0.40 | $0.10 |
| Output $/M | $2.40 | $0.30 |
| Weights | Proprietary | Open |

## Coding

- Qwen3.5 Plus: —
- Step 3.5 Flash: 42.4 (#105)

| Benchmark | Qwen3.5 Plus | Step 3.5 Flash |
|---|---|---|
| LMArena Coding | — | 1436 |
| ALE-Bench | 621.92 | — |

## Agentic & Tool Use

- Qwen3.5 Plus: —
- Step 3.5 Flash: —

| Benchmark | Qwen3.5 Plus | Step 3.5 Flash |
|---|---|---|
| Vending-Bench 2 | 0.54 | — |

## Reasoning

- Qwen3.5 Plus: 32.8 (#74)
- Step 3.5 Flash: 22.2 (#202)

| Benchmark | Qwen3.5 Plus | Step 3.5 Flash |
|---|---|---|
| NYT Connections (extended) | — | 28.4% |
| Chess Puzzles | 22% | — |
| LMArena Hard Prompts | — | 1411 |
| Mystery Game Puzzles | 17% | — |
| DTBench | 80.5% | — |
| LMCA | 36.4% | — |
| Epoch Capabilities Index | 146.78 | — |

## Math

- Qwen3.5 Plus: 49.6 (#61)
- Step 3.5 Flash: 42.6 (#84)

| Benchmark | Qwen3.5 Plus | Step 3.5 Flash |
|---|---|---|
| MathArena Final-Answer Competitions | — | 66.8% |
| OTIS Mock AIME 2024-2025 | 86.7% | — |
| LMArena Math | — | 1408 |
| FrontierMath (Feb 2025 set) | 21% | — |
| FrontierMath Tier 4 (v1) | 2.1% | — |

## Knowledge

- Qwen3.5 Plus: 46.0 (#83)
- Step 3.5 Flash: 39.6 (#132)

| Benchmark | Qwen3.5 Plus | Step 3.5 Flash |
|---|---|---|
| GPQA Diamond | 84.8% | — |
| SimpleQA Verified | 25.4% | — |
| Vectara Hallucination Rate | 10.7% | — |
| LMArena Expert | — | 1421 |

## Multilingual

- Qwen3.5 Plus: —
- Step 3.5 Flash: 50.5 (#119)

| Benchmark | Qwen3.5 Plus | Step 3.5 Flash |
|---|---|---|
| LMArena Non-English | — | 1385 |
| LMArena Chinese | — | 1447 |
| LMArena French | — | 1421 |
| LMArena German | — | 1405 |
| LMArena Japanese | — | 1354 |
| LMArena Korean | — | 1352 |
| LMArena Russian | — | 1385 |
| LMArena Spanish | — | 1419 |

## Instruction Following

- Qwen3.5 Plus: —
- Step 3.5 Flash: 73.1 (#124)

| Benchmark | Qwen3.5 Plus | Step 3.5 Flash |
|---|---|---|
| LMArena Instruction Following | — | 1385 |

## Long Context

- Qwen3.5 Plus: 43.0 (#113)
- Step 3.5 Flash: 42.8 (#117)

| Benchmark | Qwen3.5 Plus | Step 3.5 Flash |
|---|---|---|
| CL-bench | 19.8% | — |
| CL-bench Life | 12.4% | — |
| LMArena Longer Query | — | 1402 |

## Writing & Preference

- Qwen3.5 Plus: —
- Step 3.5 Flash: 58.8 (#113)

| Benchmark | Qwen3.5 Plus | Step 3.5 Flash |
|---|---|---|
| LMArena Text | — | 1403 |
| LMArena Creative Writing | — | 1357 |
| LMArena Multi-Turn | — | 1405 |

## FAQ

### Is Qwen3.5 Plus better than Step 3.5 Flash?

Qwen3.5 Plus and Step 3.5 Flash score almost the same on the Noometry Index (42.9 vs 42.3), so choose on price, context window or the category you care about most.

### Which is cheaper, Qwen3.5 Plus or Step 3.5 Flash?

Step 3.5 Flash is cheaper. It lists at $0.10 per million input tokens and $0.30 per million output tokens; Qwen3.5 Plus lists at $0.40 and $2.40.

### Which has the bigger context window?

Qwen3.5 Plus does, with 1M tokens against 256K.

### How many benchmarks do Qwen3.5 Plus and Step 3.5 Flash share?

0 benchmarks have published results for both models. Qwen3.5 Plus has 15 scored results on Noometry and Step 3.5 Flash has 19.