# Devstral Small 2505 vs Step 3.5 Flash

> Step 3.5 Flash is the stronger model overall, scoring 42.3 to 34.3 on the Noometry Index.

- Canonical page: https://noometry.com/compare/devstral-small-vs-step-3-5-flash
- Last updated: 2026-10-12
- Shared benchmarks: 0

## Summary

- The widest gap is in coding, where Step 3.5 Flash leads 42.4 to 38.9.
- Both cost about the same: $0.10 input and $0.30 output per million tokens.
- Step 3.5 Flash accepts more context: 256K tokens versus 128K.

## Snapshot

| | Devstral Small 2505 | Step 3.5 Flash |
|---|---|---|
| Provider | Mistral AI | StepFun |
| Noometry Index | 34.3 | 42.3 |
| Rank | 233 | 116 |
| Context | 128K | 256K |
| Input $/M | $0.10 | $0.10 |
| Output $/M | $0.30 | $0.30 |
| Weights | Open | Open |

## Coding

- Devstral Small 2505: 38.9 (#166)
- Step 3.5 Flash: 42.4 (#105)

| Benchmark | Devstral Small 2505 | Step 3.5 Flash |
|---|---|---|
| SWE-bench Verified (bash only) | 56.4% | — |
| SciCode | 28.8% | — |
| LMArena Coding | — | 1436 |

## Reasoning

- Devstral Small 2505: 19.7 (#252)
- Step 3.5 Flash: 22.2 (#202)

| Benchmark | Devstral Small 2505 | Step 3.5 Flash |
|---|---|---|
| Kagi LLM Benchmark | 37.7% | — |
| NYT Connections (extended) | — | 28.4% |
| CritPt | 0% | — |
| LMArena Hard Prompts | — | 1411 |

## Math

- Devstral Small 2505: —
- Step 3.5 Flash: 42.6 (#84)

| Benchmark | Devstral Small 2505 | Step 3.5 Flash |
|---|---|---|
| MathArena Final-Answer Competitions | — | 66.8% |
| LMArena Math | — | 1408 |

## Knowledge

- Devstral Small 2505: —
- Step 3.5 Flash: 39.6 (#132)

| Benchmark | Devstral Small 2505 | Step 3.5 Flash |
|---|---|---|
| LMArena Expert | — | 1421 |

## Multilingual

- Devstral Small 2505: —
- Step 3.5 Flash: 50.5 (#119)

| Benchmark | Devstral Small 2505 | 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

- Devstral Small 2505: —
- Step 3.5 Flash: 73.1 (#124)

| Benchmark | Devstral Small 2505 | Step 3.5 Flash |
|---|---|---|
| LMArena Instruction Following | — | 1385 |

## Long Context

- Devstral Small 2505: —
- Step 3.5 Flash: 42.8 (#117)

| Benchmark | Devstral Small 2505 | Step 3.5 Flash |
|---|---|---|
| LMArena Longer Query | — | 1402 |

## Writing & Preference

- Devstral Small 2505: —
- Step 3.5 Flash: 58.8 (#113)

| Benchmark | Devstral Small 2505 | Step 3.5 Flash |
|---|---|---|
| LMArena Text | — | 1403 |
| LMArena Creative Writing | — | 1357 |
| LMArena Multi-Turn | — | 1405 |

## FAQ

### Is Devstral Small 2505 better than Step 3.5 Flash?

Step 3.5 Flash is the stronger model overall, scoring 42.3 to 34.3 on the Noometry Index.

### Which is cheaper, Devstral Small 2505 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; Devstral Small 2505 lists at $0.10 and $0.30.

### Is Devstral Small 2505 or Step 3.5 Flash better for coding?

Step 3.5 Flash scores higher on coding benchmarks: 42.4 versus 38.9 in the Noometry coding category.

### Which has the bigger context window?

Step 3.5 Flash does, with 256K tokens against 128K.

### How many benchmarks do Devstral Small 2505 and Step 3.5 Flash share?

0 benchmarks have published results for both models. Devstral Small 2505 has 4 scored results on Noometry and Step 3.5 Flash has 19.