# Devstral Small 2505 vs Qwen3.5 27B

> Qwen3.5 27B is the stronger model overall, scoring 41.9 to 34.3 on the Noometry Index. Devstral Small 2505 costs 5.5× less per token, which makes it the better buy when Qwen3.5 27B's lead doesn't matter for your workload.

- Canonical page: https://noometry.com/compare/devstral-small-vs-qwen3-5-27b
- Last updated: 2026-10-11
- Shared benchmarks: 0

## Summary

- The widest gap is in reasoning, where Qwen3.5 27B leads 27.5 to 19.7.
- Devstral Small 2505 is cheaper at $0.10 / $0.30 per million input/output tokens, against $0.30 / $2.40 for Qwen3.5 27B.
- Qwen3.5 27B accepts more context: 262K tokens versus 128K.

## Snapshot

| | Devstral Small 2505 | Qwen3.5 27B |
|---|---|---|
| Provider | Mistral AI | Alibaba (Qwen) |
| Noometry Index | 34.3 | 41.9 |
| Rank | 233 | 127 |
| Context | 128K | 262K |
| Input $/M | $0.10 | $0.30 |
| Output $/M | $0.30 | $2.40 |
| Weights | Open | Open |

## Coding

- Devstral Small 2505: 38.9 (#166)
- Qwen3.5 27B: 38.9 (#168)

| Benchmark | Devstral Small 2505 | Qwen3.5 27B |
|---|---|---|
| SWE-bench Verified (bash only) | 56.4% | — |
| LMArena WebDev | — | 1358 |
| SciCode | 28.8% | — |
| WeirdML | — | 39.5% |
| LMArena Coding | — | 1427 |
| ALE-Bench | — | 349.45 |

## Agentic & Tool Use

- Devstral Small 2505: —
- Qwen3.5 27B: —

| Benchmark | Devstral Small 2505 | Qwen3.5 27B |
|---|---|---|
| Vending-Bench 2 | — | 201.98 |

## Reasoning

- Devstral Small 2505: 19.7 (#252)
- Qwen3.5 27B: 27.5 (#117)

| Benchmark | Devstral Small 2505 | Qwen3.5 27B |
|---|---|---|
| Kagi LLM Benchmark | 37.7% | — |
| NYT Connections (extended) | — | 47.9% |
| CritPt | 0% | — |
| Thematic Generalization | — | 45.5% |
| LMArena Hard Prompts | — | 1414 |
| DTBench | — | 82.4% |
| LMCA | — | 34% |

## Math

- Devstral Small 2505: —
- Qwen3.5 27B: 38.8 (#127)

| Benchmark | Devstral Small 2505 | Qwen3.5 27B |
|---|---|---|
| MathArena Final-Answer Competitions | — | 56.7% |
| LMArena Math | — | 1429 |

## Knowledge

- Devstral Small 2505: —
- Qwen3.5 27B: 38.0 (#150)

| Benchmark | Devstral Small 2505 | Qwen3.5 27B |
|---|---|---|
| Vectara Hallucination Rate | — | 12.1% |
| LMArena Expert | — | 1428 |

## Multimodal

- Devstral Small 2505: —
- Qwen3.5 27B: 39.4 (#59)

| Benchmark | Devstral Small 2505 | Qwen3.5 27B |
|---|---|---|
| LMArena Vision | — | 1241 |

## Multilingual

- Devstral Small 2505: —
- Qwen3.5 27B: 50.8 (#115)

| Benchmark | Devstral Small 2505 | Qwen3.5 27B |
|---|---|---|
| LMArena Non-English | — | 1390 |
| LMArena Chinese | — | 1478 |
| LMArena French | — | 1410 |
| LMArena German | — | 1393 |
| LMArena Japanese | — | 1345 |
| LMArena Korean | — | 1358 |
| LMArena Russian | — | 1390 |
| LMArena Spanish | — | 1407 |

## Instruction Following

- Devstral Small 2505: —
- Qwen3.5 27B: 73.5 (#119)

| Benchmark | Devstral Small 2505 | Qwen3.5 27B |
|---|---|---|
| LMArena Instruction Following | — | 1393 |

## Long Context

- Devstral Small 2505: —
- Qwen3.5 27B: 43.1 (#106)

| Benchmark | Devstral Small 2505 | Qwen3.5 27B |
|---|---|---|
| LMArena Longer Query | — | 1413 |

## Writing & Preference

- Devstral Small 2505: —
- Qwen3.5 27B: 59.3 (#111)

| Benchmark | Devstral Small 2505 | Qwen3.5 27B |
|---|---|---|
| LMArena Text | — | 1409 |
| LMArena Creative Writing | — | 1362 |
| LMArena Multi-Turn | — | 1410 |

## FAQ

### Is Devstral Small 2505 better than Qwen3.5 27B?

Qwen3.5 27B is the stronger model overall, scoring 41.9 to 34.3 on the Noometry Index. Devstral Small 2505 costs 5.5× less per token, which makes it the better buy when Qwen3.5 27B's lead doesn't matter for your workload.

### Which is cheaper, Devstral Small 2505 or Qwen3.5 27B?

Devstral Small 2505 is cheaper. It lists at $0.10 per million input tokens and $0.30 per million output tokens; Qwen3.5 27B lists at $0.30 and $2.40.

### Is Devstral Small 2505 or Qwen3.5 27B better for coding?

They score almost the same on coding (38.9 vs 38.9); test both on your own repository before choosing.

### Which has the bigger context window?

Qwen3.5 27B does, with 262K tokens against 128K.

### How many benchmarks do Devstral Small 2505 and Qwen3.5 27B share?

0 benchmarks have published results for both models. Devstral Small 2505 has 4 scored results on Noometry and Qwen3.5 27B has 28.