# Devstral Small 2505 vs Qwen3.5 Plus

> Qwen3.5 Plus is the stronger model overall, scoring 42.3 to 33.9 on the Noometry Index. Devstral Small 2505 costs 6.0× less per token, which makes it the better buy when Qwen3.5 Plus's lead doesn't matter for your workload.

- Canonical page: https://noometry.com/compare/devstral-small-vs-qwen3-5-plus
- Last updated: 2026-10-10
- Shared benchmarks: 0

## Summary

- The widest gap is in reasoning, where Qwen3.5 Plus leads 32.0 to 19.1.
- Devstral Small 2505 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 128K.
- Devstral Small 2505 has downloadable open weights; the other is API-only.

## Snapshot

| | Devstral Small 2505 | Qwen3.5 Plus |
|---|---|---|
| Provider | Mistral AI | Alibaba (Qwen) |
| Noometry Index | 33.9 | 42.3 |
| Rank | 228 | 103 |
| Context | 128K | 1M |
| Input $/M | $0.10 | $0.40 |
| Output $/M | $0.30 | $2.40 |
| Weights | Open | Proprietary |

## Coding

- Devstral Small 2505: 38.6 (#160)
- Qwen3.5 Plus: —

| Benchmark | Devstral Small 2505 | Qwen3.5 Plus |
|---|---|---|
| SWE-bench Verified (bash only) | 56.4% | — |
| SciCode | 28.8% | — |
| ALE-Bench | — | 621.92 |

## Agentic & Tool Use

- Devstral Small 2505: —
- Qwen3.5 Plus: —

| Benchmark | Devstral Small 2505 | Qwen3.5 Plus |
|---|---|---|
| Vending-Bench 2 | — | 0.54 |

## Reasoning

- Devstral Small 2505: 19.1 (#243)
- Qwen3.5 Plus: 32.0 (#67)

| Benchmark | Devstral Small 2505 | Qwen3.5 Plus |
|---|---|---|
| Kagi LLM Benchmark | 37.7% | — |
| CritPt | 0% | — |
| Chess Puzzles | — | 22% |
| Mystery Game Puzzles | — | 17% |
| DTBench | — | 80.5% |
| LMCA | — | 36.4% |
| Epoch Capabilities Index | — | 146.79 |

## Math

- Devstral Small 2505: —
- Qwen3.5 Plus: 47.9 (#55)

| Benchmark | Devstral Small 2505 | Qwen3.5 Plus |
|---|---|---|
| OTIS Mock AIME 2024-2025 | — | 86.7% |
| FrontierMath (Feb 2025 set) | — | 21% |
| FrontierMath Tier 4 (v1) | — | 2.1% |

## Knowledge

- Devstral Small 2505: —
- Qwen3.5 Plus: 46.0 (#78)

| Benchmark | Devstral Small 2505 | Qwen3.5 Plus |
|---|---|---|
| GPQA Diamond | — | 84.8% |
| SimpleQA Verified | — | 25.4% |
| Vectara Hallucination Rate | — | 10.7% |

## Long Context

- Devstral Small 2505: —
- Qwen3.5 Plus: 42.9 (#109)

| Benchmark | Devstral Small 2505 | Qwen3.5 Plus |
|---|---|---|
| CL-bench | — | 19.8% |
| CL-bench Life | — | 12.4% |

## FAQ

### Is Devstral Small 2505 better than Qwen3.5 Plus?

Qwen3.5 Plus is the stronger model overall, scoring 42.3 to 33.9 on the Noometry Index. Devstral Small 2505 costs 6.0× less per token, which makes it the better buy when Qwen3.5 Plus's lead doesn't matter for your workload.

### Which is cheaper, Devstral Small 2505 or Qwen3.5 Plus?

Devstral Small 2505 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 128K.

### How many benchmarks do Devstral Small 2505 and Qwen3.5 Plus share?

0 benchmarks have published results for both models. Devstral Small 2505 has 4 scored results on Noometry and Qwen3.5 Plus has 15.